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^7 

INTRODUCTORY 

HIS book is intended to give 
briefly the general principles 
of construction and opera¬ 
tion and instructions pertaining to 
the installation, care and use of 
internal combustion engines. Care 
has been used to avoid the extremely 
technical and to use only the sim¬ 
plest language and descriptive matter. 


















Contents 


CHAPTER 1 
Types of Engines 

Page 


Operation of the Four Cycle Type. —g 

Operation of the Two Cycle Type— 

Two Port. 10 

Three Port. H 

Combination Two and Three Port. 12 


CHAPTER 2 
Carburation 


Nature of Gasoline as Fuel. 13 

Construction of Mixing Valve. ‘ . 13 

Construction and Operation of Standard Types of Carburetors.13-14-15 

Carburetor Troubles and Suggestions— 

Impurities and Water in Gasoline. 16 

Flooding. 16 

Float’Regulation. 16 

Leaky Float. 16 

Mixtures—Rich—Weak. ' . 17 

Back Firing. 18 

Starting in Cold Weather. 18 

Repairing'Gasoline Leaks. 18 


CHAPTER 3 
Ignition 


Constituent Parts of an Ignition System. 19 

Make and Break System. 19 

Jump Spark System. 20 

Construction and Operation of Jump Spark Coil. 21 

Coil Adjustment. 22 

Construction and Operation of Jump Spark Plug. 22 

Carbon on Plugs. 23 

Testing Plugs. 23 

Construction and Operation of Timer. 24 

Spark Control. 24 

Position of Spark for Starting and Running, Advancing and Retarding 25 

Operation of Batteries. 25 

Wiring Dry Cells—Series—Series Multiple—Series Parallel. 26 

Care of Dry Cells. 27 

Wet Batteries. 27 

Storage Batteries. 28 

Charging a Storage Battery. 28 

Care of Storage Battery. 29 

Ignition Dynamo. 29 

Wiring for Dynamo and Storage Battery Floated on the Line. 30 




































Ignition—Continued 


Page 

Magneto—Low Tension. 31 

Magneto—High Tension. 31 

Spark Control on Magneto. 32 

Magneto Connections and Care. 32 

Locating Magneto Troubles. 33 

CHAPTER 4 
Lubrication 

Friction and Necessity for Lubrication. 34 

Lubricants—Kinds of. 34 

Methods of Lubricating— 

Gravity System. 35 

Pressure System. 35 

Splash System. 35 

Mechanical Force Feed. 36 

Circulating System. 36 

Mixing Oil with Gasoline.36-37 

CHAPTER 5 
Cooling 

Air Cooling. 38 

Water Circulating Pump... 38 

Thermo-Syphon System. 38 

Overheating. 39 

Failure of Pump. 39 

Solution for Freezing Weather. 39 

CHAPTER 6 
Installation 

Stationary Engine Foundation. 40 

Marine Engine Foundation. 41 

Aligning Marine Engine and Shaft. 42 

Fitting Stuffing Box and Stern Bearing. 43 

Propeller—Design and Selection of. 44 

Reversible Propeller. 45 

Reverse Gear... 45 

One Way Clutch. 46 

Thrust Bearing. 46 

Exhaust Piping. 46 

Under Water Exhaust. 47 

Muffler. 48 

Water Piping. 49 

Gasoline Tank and Piping.50-51 



































CHAPTER 7 
Wiring 

Page 

Location of Coil and Batteries... 52 

Wiring Diagrams—for Ignition..*.53-54-55-56-57-58 

Wiring Diagrams—for Lighting. 59 

CHAPTER 8 
Operation 

Preparing to Start—Starting—Stopping.• 60 

Hard to Start. 60 

Missing. 61 

Weak Explosions. 61 

Sudden Stopping. 61 

Slowing Down. 61 

Explosion in Muffler. 61 

Explosion in Crank Case or Carburetor. 61 

Pounding in Engine. 61 

Engine Hard to Turn Over. 62 

Operation Pointers.62-63 

Reversing Engine. 64 

♦ — >T—— 

CHAPTER 9 

Overhauling and Repairing 

Taking Engine Apart. 65 

Removing Piston Rings. 65 

Filing Piston Rings. 66 

Grinding Valves. 66 

Making Gaskets. 66 

Fitting New Bushings. 67 

Repairing Cracked Water Jacket. 67 

CHAPTER 10 

I 

Stationary Engines 

Governors—Hit and Miss—Throttling. 68 

To Find Size and Speed of Pulleys and Gears. 69 

Clutch Pulleys. 69 

Pulley Centers for Belting. 69 

How to Put Up Quarter Turn Belt. 69 

CHAPTER 11 

Gas and Kerosene for Fuel 

Gas Mixing Valve. 70 

Gas Consumption. 70 

Kerosene Carburetor. 70 

Starting a Kerosene Engine. 71 

Distillate and Alcohol. 71 





































Illustrations 


Page 

1. Four Cycle Engine—Its Operation. 9 

2. Two Port Engine—End of Suction Stroke. 10 

3. Two Port Engine—End of Expansion Stroke. 10 

^4. Three Port Engine—End of Suction Stroke. 11 

5. Three Port Engine—End of Expansion Stroke.j. 11 

^6 and 7. Combination Two and Three Port Engine. 12 

8. Carburetor with Compensating Air Valve. 14 

9. Carburetor—Puddle Type. 15 

10 and 11. Make.and Break Mechanism. 20 

12. Make and Break Spark Coil. 20 ‘ 

13. Jump Spark Coil. 21 

14. Vibrator of Pump Spark Coil. 21 

15. Jump Spark Plug. 23 

16. Jump Spark Timer. 24 

17. Dry Cell—Construction.... 26 

18. Dry Cells Wired in Series. 26 

19. Dry Cells Wired in Series Multiple. 26 

20. Dry Cells Wired for Double Throw Switch. 27 

21. Wet Battery. 28 

22. Storage Battery. 28 

23. Wiring for Generator and Storage Battery. 30 

24. Gravity Oiling System. 35 

25. Pressure Oiling System. 35 

26. Splash Oiling System. 36 

27. Mechanical Force Feed Oiling System. 36 

28. Circulating Oiling System. 36 

29 and 30. Oiling thru Fuel. 37 

31 Air Cooled Cylinder. 38 

32. Water Jacket and Pump. 38 

33. Thermo-Syphon Cooling System. 39 

34. Stationary Engine Foundation. 40 

35. Marine Engine Foundation. 41 

36. Installation of Marine Equipment. 42 

37. Universal Joint.... 43 

38. Combination Stern Bearing Stuffing Box. 43 

39. Stern Bearing. 43 

40 and 41. Right and Left Hand Engines and Propellers. 45 

42. Reversing Propeller. 45 

43. Exhaust Connections.. 46 

44. Plan for Submerged Exhaust. 47 

45. - Marine Muffler. 4 8 

46. Water and Exhaust Piping Plan. 49 

" 47. Water Connections. 49 

48. Pipe Terminal. 50 

49. Water Scoop. 50 

50. Gasoline Connections. 51 

51. Deck Plate. 51 

52. Wiring Cylinder Coil on Single Cylinder. 53 

53. Wiring Cylinder Coils on Double Cylinder. 53 

54. Wiring Cylinder Coils on Triple Cylinder. 54 

55. Wiring Box Coil—Single Cylinder. 54 

56. Wiring Box Coil—Double Cylinder. 55 

57. Wiring Box Coil—Triple Cylinder . 55 

58. Wiring Single Cylinder Magneto. 56 

59. Wiring Double Cylinder Magneto. 56 

60 and 61. Wiring Three Cylinder Magneto. 57 

62, 63, 64. Wiring for Magneto and Batteries .58-59 

65, 66. Wiring for Ignition and Lighting. 59 

67. Removing Piston Rings. 65 

68. Filing Piston Rings. 66 

69. Making a Gasket. 67 

70. Throttling Governor. 68 

71. Quarter Turn Belt. 69 

72. Combination Gasoline-Kerosene Carburetor . 70 






































































CHAPTER I. 


Types of Engines 

INTERNAL COMBUSTION ENGINE is a general term ap¬ 
plied to those engines deriving their power from expansion of various 
forms of gas ignited within their cylinders. Of these there are two 
separate and distinct types, THE TWO and THE FOUR CYCLE, 
the distinction being based on the manner and means by which the 
fuel charge is taken into the engine and the burned charge expelled. 

A CYCLE is a revolution of a certain period of time which 
continues to recur in the same order. As applied to the internal 
combustion engine it is the period of operation comprising suction, 
compression, expansion and exhaust. 

A FOUR CYCLE engine draws its charge directly into the 
combustion chamber thru a valve, operated either mechanically or 
by suction. This is the first or suction stroke, and occurs on the 
down stroke of the piston. On the second stroke both inlet and 
exhaust valves remain closed, the piston travels up compressing 
the gas in the combustion chamber. At the end of this second 
stroke the compressed gas is ignited by means of an electric spark 
so timed as to occur at the proper moment. The energy of the 
expanding gas drives the piston on the down stroke—the third 
quarter of the cycle—both inlet and exhaust valves still remaining 
closed. At the end of this stroke the exhaust valve is mechanically 
opened and as the piston travels up on the fourth stroke the burned 
charge is forced thru the open exhaust valve. 



Operation of Four Cycle Engine 


Thus the cycle is completed, there has been one explosion or 
impulse in two revolutions of the fly wheel or four strokes of the 
piston. The cycles continue to recur in the same order. 

A TWO CYCLE engine accomplishes the same functions—that 
is, suction, compression, expansion and exhaust—in only two strokes 
of the connecting rod, and without valves, cams, gears and the 
springs, push rods and levers necessary to operate the valves in a 
four cycle engine. 


9 






























































The method of taking the fuel into the engine has developed 
two forms of the two cycle type—the TWO PORT and the THREE 
PORT. 



Two Port Engine. Crankcase filled. 

Charge compressed in Cylinder about 
to be ignited 

starts on the up stroke it acts 
as a suction pump and draws 
a charge of fuel into the gas- 
tight crankcase. 

On the down stroke of the 
piston this charge is compressed 
to about 5 pounds pressure to 
the square inch, a check valve 
in the intake preventing it from 
escaping. As the piston nears 
the end of the down stroke it un¬ 
covers the transfer port in the 
cylinder wall and the com¬ 
pressed gas in crankcase rushes 
thru into the combustion cham¬ 
ber. A deflecting surface on 

top of the piston directs it to Two Port Engine. Burned Charge Ex- 

the top of the combustion Rusting. Crankcase Charge filling 
, t Cylinder. Crankcase suction about to 

chamber. begin 


In both forms of two cycle 
engines the crankcase is gas 
tight and the incoming 
charge is first drawn into 
the crankcase. Here it is 
slightly compressed and 
forced thru a transfer port 
in the cylinder into the 
combustion chamber. After 
the explosion the burned 
charge escapes thru the ex¬ 
haust port in the cylinder. 
Both inlet and exhaust ports 
in cylinder walls are so loca¬ 
ted that the up and down 
travel of the piston uncovers 
and closes them at the 
proper time. In the TWO 
PORT engine as the piston 


10 






























































Three Port Engine. Crankcase Charge 
Entering. Charge compressed in Cylin 
der about to be ignited 

sweeping from the crankcase 
thru the transfer port and being 
deflected upward and pushing 
out the last of the burned charge. 

Thus it is seen that suction 
in crankcase and compression in 
cylinder occur at the same time— 
the up stroke of the piston—or 
one-half a fly wheel revolution. 
On the down stroke both 
expansion, exhaust and crank¬ 
case compression are accom¬ 
plished and the cycle completed. 

One power impulse to each 
revolution. 

The THREE PORT form 
has an intake port on the 
cylinder just below the exhaust 
port. It is so located that the 
top of the piston never un- 


The piston starts on the up 
stroke, closes the transfer port, 
and compresses charge in com¬ 
bustion chamber, while at the 
same time it is drawing a new 
charge into the crankcase. 

As the up stroke of the 
piston is completed the spark 
ignites the compressed charge 
and its expanding force drives 
the piston down, compressing 
the second charge drawn into 
crankcase. 

Nearing the end of the down¬ 
ward stroke the piston uncovers 
the exhaust port in the cylinder 
wall which is directly opposite 
the inlet transfer port. The 
burned charge escapes thru this 
port while the second charge is 


Three Port Engine. Burned Charge 
Exhausting. Crankcase Charge filling 
Cylinder. Crankcase vacuum about 
to be created 






































coversJ it—so that the incoming 
charge can never get directly 
to the combustion chamber. 

Starting as we did in de¬ 
scribing the Two Port action 
with the piston down, a partial 
vacuum is created in the gas- 
tight crankcase as piston travels 
up. As it nears the top of the 
stroke the piston bottom un¬ 
covers the intake port and a 
fuel charge rushes in to fill the 
vacuum in the crankcase. 

Once the charge is in the 
crankcase the action is exactly 
the same as in the TWO PORT. 
Again we have: 

One power' -impulse to each 
revolution. 

A COMBINATION of the two and three port systems has 
proven a most efficient and powerful type of engine. In this 
system the crankcase is filled with mixture to its full capac¬ 
ity by utilizing both ports. 

Otherwise the operation is the 
same as in the straight two or 
three port type. 

So much of types. There are 
many variations and modifica¬ 
tions of the mechanical opera¬ 
tion of these forms—but the 
same principle must be em¬ 
bodied in all, namely—suction, 
compression, ignition, expansion, 
exhaust. 

The upper cut shows crank¬ 
case charge entering thru both 
second and third ports. Charge 
in cylinder about to be ignited. 

The lower cut shows burned 
charge exhausting. Crankcase 
charge filling cylinder. Crank¬ 
case suction about to begin. 


12 










































CHAPTER II. 


Carburation 

Neither liquid gasoline nor gasoline vapor alone is explosive. 
Gasoline is an hydrocarbon compound and requires some admixture 
with oxygen to make it combustible. 

By evaporation gasoline breaks up into small particles and 
mixes with the air. Air becomes saturated when it is 15 per cent 
gasoline vapor, and it is important to remember that air saturated 
with gasoline vapor will not burn. Neither will it burn when it 
is considerably below the saturation point. 

Thus knowing that neither liquid gasoline, air thoroughly 
saturated with gasoline vapor nor an extremely thin mixture of air 
and gasoline vapor will burn, it is evident that quite an exact .mixture 
of gasoline vapor and air is necessary for efficient operation of a 
gasoline engine. Therefore the development of the carburetor. 


Carburetor 

With the foregoing knowledge of the nature of gasoline as fuel 
the need of an attachment for breaking up the liquid and mixing 
it in the proper proportions with air is evident. 

A MIXING VALVE was a common form of vaporizer a few years • 
ago and is still used to some extent on motors where the speed 
is constant. It takes the form of a check valve with a gasoline 
needle valve, entering at the valve seat, to regulate the flow of 
fuel. When the suction takes place in the engine it draws the 
check open and allows a small flow of air and gasoline into the motor. 

THE MODERN CARBURETOR consists of a float chamber 
in which a cork or metal float operating an intake valve maintains 
a constant level and therefore uniform pressure of gasoline; a needle 
valve for the adjustment of flow of gasoline into the mixing chamber, 
an air intake valve; a mixing chamber in which the gasoline vapor¬ 
izes and intermixes with the air; and a throttle to control the amount 
of charge admitted to the cylinder. 

The operation of a carburetor depends entirely upon the suction 
of the engine, and as gases and liquids obey different laws of flow 
it will be understood that at low engine speeds it is necessary to 
draw the air more rapidly over the gasoline in order to pick it up. 
This is accomplished by automatically constricting the air pass¬ 
age at low speeds and providing a free air opening at high. 

A common form of accomplishing this is. by the compensating 
air valve with spring tension regulation. With this type sufficient 
air is admitted at low speed thru the free opening; as the engine speed 
increases the suction opens the compensating valve admitting 
additional air. 

Others regulate the amount of air by bronze balls seating over 
different sized openings. 


13 



A Compensating air 
valve 

B Float chamber 
C Mixing chamber 
D Spraying nozzle 
E Needle valve 
F Float 

G Reversible union 
H Float valve 
I Float connection 
Float hinge 
K Throttle 

L Float chamber cover 

| M Air valve adjusting 
screw 

N Cork gasket 
O Air valve spring 
P Throttle lever 
R Pipe connection 
S Throttle stop 
T Drain cock 
U Float valve cap 
V Flushing pin 


Float Feed Carburetor with Compensating Air Valve 


The newest development, sometimes called the puddle type, 
does away with the complexities of three or four adjustments 
necessary with the air valve type. The float is annular and the 
mixing chamber U-shaped and constricted at its lowest point where 
the air sweeps over the gasoline. 

A slight opening of the needle valve permits a shallow puddle 
of gasoline to cover the bottom of the mixing chamber when the 
engine is at rest. Thus at low speeds little suction is necessary to 
lift the gasoline, it is swept along by the air and evaporated on the 
way to the engine. At medium and high speeds the puddle is 
practically wiped out and the gasoline is taken direct from the an¬ 
nular opening and from the walls of the puddle bowl, being assisted 
both by gravity and capillary attraction. 

In this carburetor the throttle lever also operates a slide throttle 
in the air intake so that as the throttle is opened and closed the 
air is automatically increased and diminished in the proper ratio. 

Some means of adjusting the float level is essential in all float 
feed carburetors. In the older types this can be done only by taking 
the carburetor apart and bending the float hanger; the modern 
types are provided with a screw adjustment by which the float 
level can be regulated without taking the carburetor apart. 


14 



















































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A useful adjunct to the carburetor is some provision for warming 
the mixing chamber or walls of the intake pipe. Gasoline in evapor¬ 
ating absorbs heat, so that in cold weather supplemental heat is 
beneficial. This is commonly accomplished by piping hot air from 
about the exhaust pipe to the air intake. In some cases intake 
manifolds and carburetor mixing chambers are water jacketed 
and the warm overflow water from the cylinders passed around 
them. 


15 

































































































Carburetor Troubles and Suggestions 

IMPURITIES and WATER in the gasoline and changes in its 
quality are probably the most disturbing influences in carburation. 
Care in straining the fuel thru chamois when filling the tank, as 
well as a strainer in the line between tank and carburetor, will do 
much toward overcoming this. 

FOREIGN MATTER IN SOLUTION in the gasoline is difficult 
to detect. It will often gum up carburetor passages, making 
thorough cleaning of spray nozzle necessary. 

WATER IN THE GASOLINE will cause the motor to stop 
dead. The engine may readily be started again by cranking, but 
is apt to again suddenly stop. This is because water does not mix 
with gasoline, it lies in small globules in the bottom of the chamber 
and as a globule of water finds its way into the spray nozzle it cuts 
off the supply of gasoline until drawn out by cranking the engine. 
In cold weather a drop of water may freeze solid in the nozzle passage 
and entirely prevent starting. 

Water may be. removed from a gasoline tank by pouring a 
small quantity of denatured alcohol into the tank with the gasoline. 
The water mixes with the alcohol and is drawn into the engine along 
with it and the gasoline without damage. 

FLOODING. Dirt in the fuel may cause the carburetor to 
flood by sticking under the seat of the float valve so that it can not 
shut off from the tank. 

Modern carburetors are provided with a small overflow so that 
a slight flooding will cause the gasoline to drip thru the overflow 
passage. This has a double object—first to attract the operator’s 
attention and second to prevent the liquid gasoline flooding the 
cylinders. 

THE FLOAT REGULATION may be out of adjustment so 
that the float hangs too low in the bowl and must be raised above 
the spray nozzle level before it closes the valve. Adjust so that 
float has less lift. 

No definite standard can be set for the gasoline level because 
of the different degrees of vacuum in various carburetors and differ¬ 
ent suction of engines. One-sixteenth of an inch below the spray 
nozzle opening may be considered as a general approximation. 

A LEAKY FLOAT valve is indicated by dripping from the 
carburetor. 

A dense, low test grade of gasoline will cause the float to ride 
higher, thus lowering the level in the float chamber, and resulting 
in weak mixture. A readjustment becomes necessary. 

A metal float sometimes becomes punctured, and a cork float 
in time becomes saturated. In both cases flooding results. 


16 


To locate puncture in metal float submerge it in hot water—the 
gas inside will expand and bubble at point punctured. Mark this 
point—punch another larger hole to thoroughly drain float and 
solder both holes. 

A soaked cork float should be taken out and thoroughly dried— 
baking is a quick method—and several coats of shellac applied. 
Allow each coat to dry before applying the next. 

MIXTURE. A rich mixture is indicated by black smoke at 
the exhaust; popping at the carburetor denotes a weak mixture. 
The adjustment of an auxiliary air valve carburetor is best made 
with a nearly closed throttle and spark not quite up to centre. 
Under these conditions adjust the needle valve so that the engine 
runs regularly. Then open throttle and advance spark—if engine 
misses on account of too much gasoline, relieve tension on auxiliary 
air valve spring so as to give more air. 

In the puddle carburetor previously described of course no air 
adjustment is necessary. 

It is best to make carburetor adjustments with the engine run¬ 
ning under load wherever possible. 

If the exhaust piping is disconnected the mixture may be 
judged by color of exhaust flame. A rich blue exhaust flame indi¬ 
cates good combustion and therefore proper mixture; a lurid red 
flame accompanied by black smoke denotes a rich mixture—too much 
gasoline or too little air; a weak, pale, yellowish green flame sig¬ 
nifies a thin mixture—excess air or insufficient gasoline. 

The sound of the exhaust to the experienced ear is also indicative 
of the mixture. When the sound is like a “puff,” it marks a rich 
mixture; sharp, hollow low-toned exhausts may mean a weak 
mixture; a correct mixture gives sharp, smacking reports. 

•A RICH MIXTURE causes carbon to form in the cylinder and 
on the spark plug. 

If the mixture is rich the engine speed is reduced and the ten¬ 
dency is to run warm and overheat. 

A WEAK MIXTURE results in backfiring, popping. in the 
carburetor and misfiring; if allowed to continue overheating will 
occur. When the mixture is weak but not thin enough to cause 
backfiring the engine loses power. 

Dirt may cause the auxiliary air valve to stick, resulting in a 
weak mixture at low speed. 

A leaky joint or broken gasket in intake pipe between carburetor 
and cylinder results in weak mixture—often a leaky gasket will 
admit so much air that the engine can not be started. 

A leaky check valve on a two port engine will cause weak mixture 
and make the engine exceedingly hard to start. 


17 


Do not screw the inlet needle valve up too tightly—it will 
gradually wear the seat in the spray nozzle and spoil the mixture. 

BACK FIRING is the result of a slow burning charge which 
ignites the new incoming charge, causing it to fire back thru the 
intake vaVe or port. It is due either to weak mixture, or a super¬ 
heated point in the combustion chamber, which may cause ignition 
before the inlet port closes, or running under open throttle and 
retarded spark. 

Back firing may be caused by advancing spark too much when 
the engine is running slowly under heavy load. 

In a four-cycle engine back firing may also result from a weak 
inlet valve spring or a sticking or scored inlet valve. 

IN COLD WEATHER much of the gasoline is not evaporated 
and consequently not burned. It is therefore wise to open the 
needle valve wider in starting, turning it back to normal after the 
engine has thoroughly warmed up. Hot cloths, or rags wrung 
out in hot water, wrapped about the carburetor or intake pipe will 
aid the most obstinate cases in cold weather. 

High test gasoline is better for cold weather starting and running 
because it is more volatile. 

NO GASOLINE. Misfiring or total stopping of the engine 
may mean a clogged gasoline pipe. 

Be sure there is gasoline in the tank before blaming the carbu¬ 
retor. 

An air vent in the gasoline tank will help. Without it a vacuum 
is gradually formed, against which the suction of the engine must 
work in order to get a charge. 

PRIMING. It is unnecessary to prime a warm engine. 

Provision is made on most carburetors for priming by depressing 
the float. 

In starting the engine prime the carburetor, set the throttle 
only slightly open and the spark retarded. 

BEWARE OF GASOLINE LEAKS. 

Shut off main gasoline valve at tank when stopping for any 
length of time. 

A coil of copper tubing, just between the gasoline feed and the 
carburetor, to take up vibration, is excellent to prevent chafing and 
breaking the pipe connections. 

A leaky pipe or connection may be temporarily repaired by coat¬ 
ing it freely with soap and binding it tightly with strips of soapy 
cloth. 

FIRE. Do not try to extinguish a gasoline fire with water— 
that will only spread it. Cut off the air supply by smothering the 
flames with sand or use a chemical fire extinguisher. 


18 


CHAPTER Hi; 


Ignition 

The ignition is the most delicate and complex part of the engine. 
The earlier forms of ignition were by a heated projection or a direct 
flame in the combustion chamber or a hollow metal tube screwed 
into the cylinder head and heated to a cherry red by a gasoline 
torch, the compressed gas in the combustion chamber being 
ignited by coming in contact with the glowing hot surfaces. 

Present day ignition is almost entirely by the electric spark, 
which requires: 

(1) A source of current— 

(a) Dry batteries (d) Generator 

(b) Wet batteries (e) Magneto 

(c) Storage battery (accumulator) 

(2) An induction coil by which an induced current is created 
of far greater intensity than that of the battery. This induced 
current is of sufficient pressure to form a spark at the breaking point 
of the circuit. 

r (a) The functions of the induction coil are sometimes embodied 
in the magneto. 

(3) A method of closing and opening the circuit at the proper 
time with relation to the position of the piston in the cylinder. 

(a) A timer, or commutator, in the Tump Spark. 

(b) A mechanism of cams, rods and springs in the Make and 
Break. 

(4) A plug, fitted into the cylinder head, containing two 
electrodes insulated one from the other. 

(a) The Jump Spark Plug has no moving parts and the current 
arcs from one electrode to the other. 

(b) The electrodes of the Make and Break plug are mechanically 
operated so that they are brought together, closing the circuit, 
and quickly snapped apart, opening it so that a spark occurs. 

(5) A switch for closing the ignition circuit for running the 
engine and”opening it so there can be no possible waste of current 
while idle. Opening the switch is of course the quickest and most 
effectual means of stopping the motor. 

(6) Wiring for connecting the various parts of the system into 
a complete electrical circuit. 

(a) Primary or low tension wire for the Make and Break. 

(b) Both primary and secondary (high tension) for the Jump 
Spark. 

The method of bringing about a spark in the combustion chamber 
has developed two distinct types commonly known as the JUMP 
SPARK and the MAKE and BREAK. 

Make and Break System 

The Make and Break, or Contact spark, is possibly slightly 
simpler electrically than the Jump Spark, but is mechanically 
much more complex. The percentage of engines—automobile, 


19 





marine and stationary—using this form of ignition 
is small in comparison with those usingthe Jump Spark. 
From the following description it will be seen that the 
Jump System is much simpler of control, gives a wider 
range of speed, a more flexible engine and is easier to 
adjust and repair. 

The essential parts of the Make and Break system 
have been previously mentioned and we can give here 
but briefly the general construction and operation of 
those parts which differ from the Jump System. 

The coil is a primary induction coil composed of 
a bundle of soft iron wires (about 20 gauge) called 
the core, encased in insulation, around which are wound 
a few layers of insulated copper wire (about 18 gauge) 
called the primary winding. The 
Exterior Make flow of current thru the winding 
Break creates a magnetic field and mag- 
netizes the core. If the current 
is stopped the magnetic field also ceases, 
which causes an induced current to be formed 
in the coil and a spark occurs at the point 
where the current is broken. As the resist¬ 
ance of air to the flow of the lines of force 
is so much greater than that of soft iron, the 
magnetic effect is enormously increased by 
the core. This form of spark will not jump 
across a space between two points but occurs only between the 
points of contact on the breaking of the contact. 

Thus it will be seen that in this system the two points, or elec¬ 
trodes, of the plug must be movable within the cylinder and me- 

chanically operated so that just 
at the right instant they will 
come into contact, closing the 
circuit, and immediately break 
apart, causing the induced cur¬ 
rent to spark at the point of 
breaking. 

The contact is usually brought about by a cam on the shaft 
operating a trip rod; a spring is used to cause the break. 

This system has the mechanical disadvantage of requiring gas 
tight, heat resisting, moving parts in the excessive heat of the 
combustion chamber. 



Interior Make and 
Break Mechanism 



Jump Spark System 

The Jump Spark is mechanically much simpler than the contact 
spark and is used by the vast majority of manufacturers. By 
this system the high tension current causes a hot spark, or series of 
sparks, to jump the gap between the ends of the two electrodes of 
the spark plug screwed into the combustion chamber. 

The JUMP SPARK COIL has the core and primary winding 
of the Make and Break coil; the primary winding is encased in 
insulation around which is wound the secondary, several thousand 


20 

































» 


feet of fine insulated copper wire (about 36 gauge). The jump 
spark coil is also provided with a condenser, consisting of alternate 
sheets of tin foil and waxed paper, and a magnetic vibrator. 



The current from the battery or magneto flowing thru the primary 
winding produces an induced current in the secondary winding, 
the effect of which depends on the rate at which the current in the 
primary dies out. As has been shown in the Make and Break coil 
the breaking of the current causes self inductance in the primary 
which prevents the current from breaking quickly. A condenser 
is therefore incorporated in the coil to store this self induced current 
and thus neutralize its effect, allowing the current in the primary 
to die down almost instantly, thereby inducing a high pressure in 
the secondary. 

If the primary current be rapidly interrupted while the circuit 
is closed the intensity of the secondary current will be greatly 
increased. This intermitting of the primary current was originally 
accomplished by a mechanical vibrator which was made a part of 
the engine. Now however, the automatic magnetic vibrator has 
'become a part of the coil. 

The vibrator is placed at one end of the coil where it may be 
affected by the core. It consists of a platinum pointed contact 
screw, a platinum pointed vibrating spring, a soft iron armature 
and a bridge for mounting and holding the parts of the vibrator in 
place. The connec¬ 
tions inside the coil 
are so made that to 
complete the pri¬ 
mary circuit the < ^ ON ' r * e ‘ r po,NTa ' 
current passes thru 
the vibrator bridge, 
contact screw and 
spring to reach the 
primary terminal. 

The condenser is 
also connected to 

the vibrator. Magnetic Vibrator Jump Spark Coil 



ADJUSTING 3<R6W 

3bt Nut 

Via^ATo* 'Swina 


♦ 


21 


































































Now when the contact points of the engine timer form a closed 
circuit the core is magnetized and attracts the armature of the 
vibrator. This pulls the platinum points apart, breaking the primary 
current and inducing a current in the secondary winding. As 
explained in the Make and Break coil a spark occurs where the 
primary current breaks—which in this case is at the platinum 
points of the vibrator. However, the condenser is connected to 
the two terminals ol the vibrator so that the current causing the 
arc is stored in the condenser and no spark occurs if the condenser 
is of sufficient size and uninjured, and the vibrator adjusiment is 
perfect. The instant the primary current is broken by the vibrator 
points being pulled apart the core is demagnetized, releasing the 
vibrator spring which resumes its normal position in contact with 
the screw—the circuit is thus closed again and the operation con¬ 
tinues to repeat itseli so long as the engine timer points^are in 
contact. 

This interruption of the primary and the resulting building 
up of the secondary current continues while the timer points are in 
contact and a series of sparks jump the gap in the plug. 

Coil Regulation 

Ignition should occur regularly with a minimum coil consumption 
of current, which ranges from .25 to 1.2 amperes according to engine 
and coil construction. The higher the engine compression the 
greater the amperage required. 

The tension of the vibrator spring determines the coil consump¬ 
tion of current. Therefore unless the engine has exceptionally 
high compression the tension of the spring should be light. 

Frequently it will be found that the vibrator will buzz all right 
when the motor is turned over by hand, but when running it fails 
to respond. This may be a result of too stiff a tension on the 
vibrating spring so that when quick contacts are made the stiff 
spring does not have time to vibrate properly. 

When the adjusting screw is turned down too tight the coil 
consumes an excess of current and burns away the platinum points. 

Do not drive nails or screws into the coil—you may puncture 
the condenser, break an internal connection or damage the insulation. 

Do not try to take a coil apart—you will only ruin it beyond 
repair. 

When a coil goes wrong from an internal breakdown it is usually 
quicker, safer and cheaper to buy a new coil. 


Plug 

THE JUMP SPARK PLUG is a simple, durable and inexpensive 
affair. It consists of a metal shell which screws into the engine, 
making^ contact thru the engine with ihe ground wire. Fitted 
tightly thru the shell is an insulated electrode of heat resisting 
alloy. Another electrode is made a part of the shell and the points 
of the two are brought about one thirty-second of an inch apart. 


22 



Jump Spark 
Plug 


The high tension wire from the coil is fastened to 
the terminal of the insulated electrode and the 
secondary current arcs the gap from it to the shell 
electrode, igniting the charge. 

Mica and porcelain are the general non-conductors 
used for insulating plugs. 

The operation of a plug is affected either by injury 
to the insulation or changing the relative position of 
the points. A small crack in the insulator will allow 
the current to escape before reaching the points. The 
insulator may become covered with a coating of con¬ 
ducting material—water on the outside or carbon on 
the part within the combustion chamber—allowing 
the current to “sneak” across instead of arcing at 
the points. The insulator may become impregnated 
with a conducting matter—oil—and allow the current 
to leak thru. 


A porcelain plug may crack or break from a blow or from a sudden 
change of temperature—a dash of cold water on a hot porcelain 
plug will frequently crack it. A blow or strain may cause the mica 
washers of a mica plug to separate allowing the current to escape. 

The jump spark plug will sometimes fail to give satisfactory 
results simply from a loose core. This can be easily remedied by 
tightening with a wrench the pack nut which screws into the shell 
and holds the core firmly. 

CARBON IN PLUGS. A rich mixture causes imperfect 
combustion and results in carbon in the form of soot or lampblack 
being deposited on the insulating surface. 

An excess of oil will quickly cause a carbon deposit. 

Porcelain so long as the glaze is not burned off will not absorb 
conductive matter, but in time the extreme heat deteriorates the 
insulation. 

A perfect mixture and the proper amount of good lubricating 
oil will permit a plug to be run indefinitely without carbonizing. 

The points of the plug should be made of a heat-resisting alloy 
so that they will not burn away too rapidly and also not warp 
under heat and thus change the distance of the gap. The points 
should also be strong enough not to bend in handling. 

Always carry at least one extra plug so that when a plug fouls 
a quick change can be made. 

TESTING PLUG. In putting a new plug in the engine see 
that the spark gap is right—about one thirty-second of an inch, a 
little less where a high tension magneto is used—and do not strike 
the points against the cylinder when placing it. It is a good idea 
when putting in a new plug to attach it to its secondary wire, rest 
the shell on a part of the engine, seeing that the metal terminals 
of the insulated electrode do not touch the engine anywhere, and 
short circuit the timer for that cylinder. You can then see the 
spark jump the gap in the plug. When making this test do not 
rest the plug near the plug hole in the cylinder as the spark will 
ignite any unburned charge in the combustion chamber, risking 
fire or personal injury. 


23 










Timer 


A timer, or commutator, is necessary for closing and opening 
the primary circuit at the exact moment the charge is ready for 
ignition. 

Probably the simplest form of timer is the brush contact type 
consisting of a round fibre with copper contact point set in it and 
extending toward the centre until it touches the metal bushing of 
the fibre bore, and a metal housing holding one insulated contact 

brush of brass for each cylinder of the 
engine. If there are two cylinders there 
are two brushes exactly opposite each other, 
or at 180 degrees—if three cylinders the 
three brushes are set at 120 degrees—if 
four cylinders the brushes are set on the 
quarter or 90 degrees, and so on. 

The contact fibre is rotated within and 
in the same plane with the housing, which is 
held stationary, and every time the metallic 
segment wipes across a brush in the housing 
a primary circuit is established. 

Jump Spark Timer It is now customary on marine engines to 

place the timer on an elevated shaft where it 
is free from oil, grease, dampness and dirt and is easily accessible. 

As the four cycle engine explodes only every other revolution 
the contact fibre must rotate at one-half engine speed; with the 
two cycle exploding each revolution the rotation must be at engine 
speed. 

Contact in the timer must be made and broken at a fixed point 
with relation to the position of the piston in the cylinder; in case of 
multiple cylinder engines the timer must be accurately constructed 
so that this point is the same in all cylinders. 

A timer should provide accurate timing of the spark—a good 
electrical contact—a clean break of the circuit—careful insulation 
and fulfill its functions with as little wear as possible. 

Delicate adjustments on a timer should be avoided, simplicity 
should be sought. 

SPARK CONTROL. In order to slightly vary the time of 
ignition with relation to the position of the piston in the cylinder, 
and thereby control to a certain extent the speed of the engine, the 
timer housing is mounted so that it can be rocked on its axis. 

When the housing is moved in the same direction that the 
contact fibre rotates the spark is retarded, it being evident that the 
contact point must travel further before making contact with the 
brush. The piston has at the same time continued that much farther 
on its cycle before the spark occurs. 

An advanced spark is therefore obtained by moving the housing 
in the opposite direction so that the segment of contact in the 
fibre reaches the brush sooner. 



24 

























A RETARDED SPARK tends to decrease the engine speed 
because it takes place after the piston has started on the downward 
stroke after compressing the charge. Thus the compressed charge 
is somewhat relieved and when it is ignited it has lost some of its 
expanding force, nor is the combustion of the gas completed when 
the exhaust port or valve opens. 

BY ADVANCING the time of spark to take place before the 
piston has quite reached the top of the compression stroke the gas 
becomes thoroughly ignited and its expanding force is enhanced, 
the speed and power of the motor are increased. 

A spark too much advanced will cause a pronounced knock in 
the cylinder; this is particularly noticeable when the engine is labor¬ 
ing to its full capacity. In this case the spark should be retarded 
slightly—’enough so that the pound ceases. 

Water or greasy grit in a timer will form a conducting surface 
over the insulation and frequently cause a continuously closed 
circuit and unbroken spark. A loose strand of wire from the in¬ 
sulated terminal coming in contact with the timer housing will 
have the same result. If your coil should buzz continuously look 
for one of these conditions. 

The above condition in a multiple cylinder engine may not 
stop it altogether, but by exploding the charge while the ports or 
valves are open will cause explosions in the carburetor or muffler. 

STARTING AND RUNNING. The spark should always be 
retarded on starting. An attempt to crank a motor with an ad¬ 
vanced spark fires the charge while the piston has only partly trav¬ 
eled the up stroke, results in a “back kick” and a broken arm or 
leg may follow. 

It is more economical and better results from the engine are 
obtained by running with a slightly advanced spark and controlling 
the speed as much as possible with the throttle. 

When the spark is retarded the mixture should be throttled as 
much as possible—otherwise the spark and throttle are really 
working against each other, fuel is wasted and overheating of the 
engine results. 

In speeding up an engine the spark should first be advanced— 
then the throttle opened. To slow down the throttle should be 
closed and then if still slower speed is desired the spark should be 
retarded. 


Batteries 

The dry cell has long been used as the source of current for 
engines which are not run continuously for hours at a time. Even 
for prolonged running they are often used wired in series multiple. 

A dry cell consists of a zinc element, a carbon element, an exciting 
fluid (electrolyte), material for holding the electrolyte by saturation, 
and a chemical depolarizer. The zinc element is made in the form 
of a can and acts as a retainer for the rest of the cell. Around 
the inside of it is placed the material saturated with electrolyte— 


25 




it may be a paste, blotting paper or any 
composition capable of holding the liquid 
as a sponge holds water. The carbon 
element is placed upright in the centre 
of the cell and around it is tightly packed 
a composition of carbon flour and oxide 
of manganese, also saturated with the 
electrolyte. A sealing compound is then 
poured over the top to hold the elements 
in place and prevent the leaking and 
evaporating of the electrolyte. 

Carbon and zinc have a different 
potential which causes the current to 
flow from the one element to the other. 
The potential of carbon is greater than 
that of zinc and the strength of flow 
depends upon this difference which is, measured electrically, about 
1.5 volts with the average dry cell solution. 

During the electro-chemical action of the electrolyte, which 
is largely composed of salammoniac, hydrogen is generated at the 
carbon element. This clings to the carbon, and being a poor 
conductor quickly^ reduces the current. This action is called 
polarization. The depolarizing compound is therefore introduced 
which gives off oxygen, this combines with the hydrogen and counter¬ 
acts its polarizing effect. 

Wiring Dry Cells 




A set of dry cells 
for ignition may con¬ 
sists of from four to 

- Dry^Cells Wired in Series six ceils in series; the 

carbon oi one cell 
connected to the zinc^of^the next as illustrated. This gives a 
current with the same amperage as one cell and a voltage equal to 
that of one cell multiplied by the number of cells in the series. 

Longer life may be 
obtained from dry cells 
by connecting them in 
series multiple as here 
shown. By this method 
the voltage is equal to 
that of the combined cells 

in one series and the am- _ „ „ .. 

perage equal to that of ry s Wlrecl ln Senes Multiple 

one series multiplied by the number of series. Thus with twelve 
batteries of 20 amperes each, in series multiple, with four 1.5 volt 
batteries to a series and 3 series, the total voltage would be 6 and 
the amperage 00; the same batteries in series multiple with six 
cells to a series and two series would produce a current of 9 volts 
and 40 amperes. 



26 





























If dry batteries 
form the only source 
of current it is ad¬ 
visable to carry two 
sets. 


Wiring for Two Sets Batteries to DouDle Throw 
Switch 


If two sets of dry 
cells are used it is 


wise to run for a time on one set and then switch to the other 
and continue alternating. 

A cell with high initial amperage, over 22 to 25 amperes, is most 
likely to run down quickly. 


Care of Dry Cells 

Dry^cells are affected by either extreme heat or cold and should 
therefore be kept in as uniform temperature as possible. 

Dropping or severely jarring a cell will usually ruin it or at 
least make it short lived. 

Care should be exercised chat no metal is placed so as to touch 
the terminals of a series ox batteries; this will cause a rapid discharge 
of the ceus. See that wrenches or other tools are not carelessly 
laid on top of the batteries. Do not keep the engine timer on 
contact longer than necessary when adjuscing coil as it has the 
same effect. 

A weak set of dry cells will recuperate considerably if not used 
for a short time. 

Always be sure that all battery terminal nuts are screwed down 
tightly on the connecting wires. 

Weak batteries are indicated by the missing of the engine, at 
first only spasmodically but increasing quickly as the batteries grow 
weaker. 

Dry cells should be tested individually with an ammeter.. New 
cells usuaiiy register from 18 to 25 amperes. Cells in series are 
usually about useless for ignition when under 10 ampeies; when in 
series multiple they may be run much lower. One weak cell in a 
sec weakens the current from the entire set. 

It is better to cut a dead cell from a set entirely, if it can not be 
replaced, than to try to run with it wired in. 

When the engine is stopped the switch should always be opened 
so that if the timer should stop with the points in contact no short 
circuit will result. 


Wet or Primary Battery 

The wet cell has not been used extensively in marine or automo¬ 
bile work but fills a wide field with stationary engines. Although 
the first cost is greater than that of the dry ceil its life is three or 
lour times as long. It furnishes a current of practically constant 
voltage and its parts are renewable at a slight cost. 

The usual primary battery consists of a copper oxide plate 
forming the positive pole and a zinc plate forming the negative pole, 

27 






suspended from a porcelain cover in a porcelain 
or enameled steel jar containing a liquid solu¬ 
tion of caustic soda. The liquid is covered 
with a layer of paraffin oil to prevent evap¬ 
oration and leakage. 

When a battery is exhausted new poles, 
liquid and oil may be obtained at about one 
third the cost of a new battery and the cell is 
as good as new. 

From four to seven cells are required for a 
set according to the type of engine and ignition. 


Storage Battery or Accumulator 


The storage battery is used extensively for automobile ignition 
and is becoming more popular in marine service. When used 
in connection with a small dynamo it may be used in furnishing a few 
small electric lights as well as current for ignition. 

This form of battery ordinarily consists of two sets of lead 
plates immersed in dilute sulphuric acid, the whole contained in a 
hard rubber jar. The positive plate is brown 
in color and contains peroxide of lead, the 
negative is light grey and contains spongy 
lead. By connecting the terminals to the 
poles of a dynamo and passing a current 
thru the battery an electro-chemical action 
is generated; in discharging a reverse action 
takes place. 

Large current output, a constant voltage 
and the fact that it can be recharged com¬ 
mend the storage battery. On the other 
hand it requires more careful attention than 
the dry or wet battery and a charging source is essential. 

CHARGING. When the voltage drops to 1.8 the battery should 
be at once recharged. If the battery is discharged too far or is 
kept standing in a discharged condition a chemical change occurs, 
a non conductor (lead sulphate) forms on the plates and they 
become worthless. 



Storage Battery 


In charging an accumulator the rate of charge should be slow, 
from 4 to 8 hours being required, the current must be direct and the 
positive pole of the generator must always be connected to the posi¬ 
tive terminal of the battery. The voltage of the charging current 
should be from 20% to 30% higher than that of the battery. 

A battery should be charged to about 2.5 volts per cell. On 
discharging a rapid drop will occur to about 2 volts where it will 
remain for some time. 

It is beneficial to overcharge an ignition battery about once in 
three months by charging to 2.05 volts. 

If possible a battery should be recharged immediately after 
becoming discharged. When immediate recharge is impossible the 
battery should not be discharged further than 1.85 volts. 


28 




























Batteries should be charged in a room with plenty of ventilation. 
Battery caps should always be removed when charging. If cells 
heat the voltage of the charging current should be reduced. 

If the battery is not to be used for some time it should be slightly 
over charged and every three or four weeks a small additional charge 
should be given. If the battery is to be out of service for a consid¬ 
erable time, it should be fully charged at a slow rate, then partially 
discharged and the acid drawn off. This acid may be saved in 
glass bottles for future use. The plates should be thoroughly 
washed in running water and then allowed to stand in pure water 
for twenty-four hours, changing the water frequently. 

Over charging and too rapid discharging cause sulphate to 
form on the plates which is most injurious. 

THE ELECTROLYTE should be one part chemically pure 
sulphuric acid to about four parts distilled water. This should be 
mixed in a separate acid proof vessel—lead or glass—by pouring 
the acid slowly into the water and stirring. Never pour the water into 
the add. After mixing, the electrolyte should be allowed to cool 
before it is poured into the battery. The specific gravity of the 
electrolyte varies from 1.200 to 1.250. 

The battery plates should be entirely immersed; if they are 
uncovered thru evaporation add pure water. 

The usual ignition accumulator consists of three 2 volt cells 
a 6 volt 60 ampere hour battery. 

Terminals and metal parts of a storage battery should be given 
frequent coatings of vaseline to protect them from the acid and insure 
perfect connections. 

Sediment in the bottom of a cell or impurities in the electrolyte 
may cause internal short circuiting. 

If the plates are not entirely covered with acid that part above 
becomes oxidized and the strength of the battery is correspondingly 
decreased. 


Dynamo and Magneto 

The use of a mechanical generator as a source of current is now 
quite general in automobile, marine and stationary practice. Either 
a dynamo or magneto will furnish the required current, the magneto 
being in more general use. 

With a mechanically generated current there is no particular 
necessity of economy in its use. It offers a constant source of as 
much current as is required, while a battery of any type contains 
but a fixed amount which should be used with economy. 

THE DYNAMO has given way almost entirely to the magneto 
for ignition except where used in conjunction with a storage bat* ery. 
An ignition dynamo is of the self-exciting,. shunt wound, direct 
current type, the field magnets being of soft iron wound with wire. 
It is therefore not self regulating it may overheat and burn out if 
run at too high a speed, and will not generate sufficient current at 


29 


low speed. A dynamo usually must run at from five to six times 
engine speed (1800 to 2500 R. P. M.) and will permit of little varia¬ 
tion. A governor is therefore necessary to prevent it from over 
speeding when the engine races. Inability to generate at low speed 
makes it impossible to start on the dynamo so the start must be made 
on batteries, switching to dynamo when the engine has attained 
sufficient speed. This varying current also causes excessive burning 
of the coil vibrator points. 

Dynamo and Storage Battery 

When used in connection with a storage battery the dynamo 
forms a most satisfactory ignition system. It is particularly adapt¬ 
able for boat use where a little weight is of no particular moment, 
especially as in this way lights may also be taken from the current. 



Wiring for Generator and Storage Battery 


In this system the dynamo is usually driven by friction from the 
engine fly wheel, or by belt, and is equipped with an automatic 
speed regulator. The dynamo voltage is arranged slightly higher 
than that of the battery, the system is so wired that all current is 
taken direct from the battery and while running, the dynamo is 
constantly charging the battery. An automatic cut-out is used 
which disconnects the dynamo and battery when the engine stops 
so that the battery current can not discharge thru the dynamo. 

By this system, known as “floating the battery on the line,” 
the battery is kept charged, lights may be furnished even when the 
engine is not running, and there is usually sufficient charge in the 
battery to get home on should the dynamo fail. 

Current generated by a dynamo is low tension and a coil is re¬ 
quired with it. 


30 

















Low and High Tension Magnetos 


THE MAGNETO differs from the dynamo in that its fields 
instead of being temporarily excited are permanent magnets 
and its current is alternating. 


The armature consists of a soft iron core and a wire winding. 
By revolving the armature, or as in some types an inductor consist¬ 
ing of two diametrically opposite soft iron cylindrical segments, 
the magnetic lines between the two magnetic poles are rapidly 
passed thru the core and snapped out. On the next half revolu¬ 
tion they are snapped in and out again in the reverse direction and a 
current is formed and broken. 


A LOW TENSION MAGNETO for Make and Break or Jump 
spark may be provided with a governor and driven by friction from 
the fly wheel, or by belt. With this system the regular coil is re¬ 
quired, altho it is sometimes incorporated in the magneto, and it is 
usually impossible to start the engine on the magneto. 

THE HIGH TENSION MAGNETO has two windings on the 
armature corresponding to the primary and secondary windings of 
a jump spark coil. This type of magneto must be gear driven at 
an exact speed in proportion to the engine revolutions. No engine 
timer is required, the spark occurring regularly as the core and poles 
make and break the magnetic lines; but the proper ratio of gearing 
is necessary and a distributor is incorporated in the magneto to 
direct the current to the proper bylinder. 


The magneto must run at engine speed for one and two cylinder 
two cycle and eight cylinder four cycle engines; at one and one- 
half times engine speed for a three cylinder two cycle engine; at 
twice engine speed for a four cylinder two cycle; and at one-half 
and three-quarters engine speed for four and six cylinder four cycle 


engines. 

- When this type of magneto is furnished it is usually mounted 
complete on the engine by the manufacturer so there is small 
danger of derangement of the drive. Occasional lubrication, 
cleaning and adjustments of the make and break points and insula¬ 
tion, and tightening connections is about all the attention necessary. 
The modern magneto is a simple, positive, well made mechanical 
device, it cannot deteriorate, needs no renewals and requires little 

attention. 


One of the largest manufacturers of high tension magnetos 


says; 

“This magneto does not produce a steady flow of current, but 
creates two impulses during each revolution of the armature. T e 
magneto must always run in such relation to the engine crank shaft, 
that a wave of current is present at the instant when the piston 
in the position to receive a spark. A device known as the interrupt 
or circuit-breaker, which is attached to the armature shaft revolves 
with it and controls the instant at which the ignition spark occurs, 


31 


it is so arranged that it breaks the circuit once during each revolu¬ 
tion for a one-cylinder engine, and twice during each revolution 
for an engine of two or more cylinders. When its platinum points 
are together, they provide a path by which the magneto current may 
flow, and it is so set that the platinum points are closed during the 
periods when the magneto current is weak. At the instant when 
the magneto current reaches its greatest intensity, the interrupter 
lever is moved on its pivot by cams or blocks, and the separation 
of the platinum points diverts the current from its regular path and 
causes it to flow to the spark plug. 

“TO ADVANCE or RETARD THE SPARK, the housing 
that supports the steel blocks is rotated slightly by means of an 
arm provided for the purpose. This movement causes the interrup¬ 
ter lever to break contact earlier or later in the rotation of the arma¬ 
ture and makes a corresponding difference in the point of the stroke 
at which the spark occurs. 

“The magneto produces its current through the rotation of the 
armature between the ends or poles of powerful horse-shoe magnets. 
Because of the material used for the magnets and of the arrangement 
of the parts, the magnetism is retained almost indefinitely, and the 
magneto is, therefore, a practically constant source of current. 

“It must be borne in mind, however, that a magneto must not 
be taken apart, for this is the surest way of causing the loss of 
magnetism; the magnets must not be removed and the armature 
must not be withdrawn. Certain seals in the magneto will form 
a sure indication of the removal of the magnets or the withdrawing 
of the armature. 

“The parts that are meant to be removed, such as the inter¬ 
rupter housing, the interrupter, the carbon brushes, and on mag¬ 
netos for engines with three or more cylinders, the distributor 
plate, may be taken off with ease. 


Connections and Care 

“A magneto possesses a. low tension terminal and in addition 
a high tension terminal for each cylinder of the engine for which 
it is intended. The low tension terminal is to be connected to one 
pole of the switch, while the other pole of the switch is to be grounded 
on the metal of the engine. 

“When the switch is closed it provides a path by which the 
current may flow from the low tension terminal to ground, and this 
will render it impossible to produce a high tension spark. 

“TO OPERATE ON THE MAGNETO the switch must be 
open, while to shut the engine down and to render the magneto 
inoperative the switch must be closed. 


32 


“The care to be given to a magneto consists in oiling it once every 
hree or four weeks with a few drops of good oil applied at the oil 
noles at each end of the instrument. The parts of the interrupter 
must not be oiled, as they are constructed to operate without 
lubrication. If there is an excess of oil on them it will interfere 
with the free operation of the interrupter lever. 

“After long service the platinum points of the interrupter may 
be corroded, and in that event, they should be cleaned and trued 
by the use of a very fine flat file; they should then be adjusted so 
that when the interrupter lever is resting on a cam the gap between 
the platinum points will be about 1-64 of an inch, or the thickness 
of the metal gauge that is pivoted to the wren h accompanying 
the magneto. 

“Beyond oiling, the magneto should be left alone. 

Locating Troubles 

“The principal difficulty that will be encountered with magneto 
ignition is due to the mis-adjustment of the spark plug points. 
The distance between the points of the spark plug should be about 
1-50 of an inch, and in no case as wide as 1-32 of an inch. 

“After long service the intensity of the magneto current will 
burn away the points of the spark plug and widen the gap. If 
this condition is encountered it should be corrected by closing the 
points until the gap is of the correct dimension. 

“If a secondary cable is disconnected from the magneto while 
the engine is in operation, a spark will be observed passing in the 
safety spark gap located under the arch of the magnets. The 
alectric pressure produced in the magneto winding is very great) 
and if a proper path is not provided for it thru a spark plug, 
the safety spark gap will permit it to flow and will thus protect the 
nagneto windings. 

“If the magneto apparently fails to produce a spark the switch 
may be found to be closed, or if this is not the case the wire from the 
low tension terminal of the magneto to the switch may be in contact 
with metal. This may be determined by disconnecting the wire 
from the low tension terminal. If no spark is produced under this 
condition, one of the secondary wires should be disconnected from 
the magneto and the motor cranked briskly. If the magneto is in 
good condition a spark will be observed passing in the safety spark 
gap. If no spark is observed the cover of the interrupter housing 
should be removed and an inspection made to determine whether 
the interrupter lever will move freely on its bearings. 

“In practically every case the trouble will be located^at one of 
these points, but if after an examination and test the magneto still 
fails to produce ignition it should be returned to the makers. 


33 


CHAPTER IV. 


Lubrication 

Friction is the resistance of two surfaces rubbing or rolling against 
each other. The object of lubrication is to minimize this friction 
by interposing a film of oil between the moving bodies, thus sub¬ 
stituting a liquid and lesser resistance. 

No matter how accurately the surfaces are finished, nor how 
smoothly, there are still minute irregularities. By rubbing two 
surfaces together under pressure these irregularities are broken 
and ground off, generating heat. Therefore increased roughness 
or increased pressure causes friction, and large bearings should be 
used to distribute the pressure in order to lessen the risk of abrasion 
and seizure. It is thus evident that careful machining, bearings 
of ample size and positive method of lubricating all bearing surfaces 
are of the utmost importance in an engine. 

The question of lubrication must be considered under two heads: 
—the kind of lubricant and the method of lubricating. The very 
nature of the internal combustion engine with its extreme heat and 
internal pressure makes it a problem apart from ordinary 7 machinery 
lubrication. 


Kind of Lubricant 

Gas engine oil should have enough body (viscosity) to keep it 
between the bearing surfaces at their greatest heat and pressure, 
but must still maintain its fluidity. It must be a good conductor 
of heat, free from acids, grit and water. Must not vaporize at high 
temperature nor decompose at low. Only the best pure mineral 
oil should be used—never an animal or vegetable oil or grease. 

Lubricating oil in a cylinder is at the same temperature as the 
cylinder walls, from 180 to 300 degrees. Heavier oil should be 
used with a cool engine, or in a large cylinder where the pressure is 
great or where piston speed is extremely slow. 

The oil in a cylinder is finally decomposed or evaporated after 
serving its purpose, and if a proper quantity of good oil is used it 
is eventually practically all forced out with the exhaust. 

The cutting, seizing or burning out of a bearing is always due to 
the failure to keep a film of oil between the bearing surfaces. This 
may result from lack of oil, too thin oil or excessive pressure. Ex¬ 
cessive pressure may result from a loose bearing which will heat as 
easily as a tight bearing. 

A close fit when cold becomes a tight fit under the heat of working 
conditions. More oil should be given a new engine than one which 
has been run long enough to “find its bearings.” 


34 


GREASE FOR LUBRICATING the main shaft bearings is 
popular because of its cleanliness and freedom from dripping. 

For reverse gears a heavy, viscous oil should be used in prefer¬ 
ence to a light oil or grease. Light oil will be pressed from between 
the gear teeth and fail to lubricate; grease, because it does not spread 
easily, is forced away from the parts it should lubricate, it also 
carries particles of grit and metal from the bottom of the case. 

Methods of Lubricating 

Systems of lubrication are by gravity, 
pressure, splash, force feed, circulation or 
thru the fuel. The gravity oiler is simple 
but must be watched and regulated, as the 
rate of flow is affected by temperature and 
the clogging of oil passages. A gravity oiler 
must always be turned on when the engine 
is started and shut off when stopped. 
Neglect of this has caused many a burned 
out bearing and scored cylinder wall. 


Gravity Oiling System 

In the PRESSURE 
SYSTEM compression 
from the crank case or 
explosion chamber is con¬ 
ducted to the surface of 
the oil in the lubricator, 
forcing the oil thru the 
various feed pipes. The 
rate of flow may be ad¬ 
justed by needle valves. 

The pressure system is 
not infallible as some of 
the feeds may become ob¬ 
structed. Pressure Oiling System 

THE SPLASH SYSTEM depends upon automatically or me¬ 
chanically maintaining a positive^level of oil in the crank case, into 
which the connecting rod dips, whipping the oil to foam and 
splashing all working parts. The great difficulty in this system is to 
maintain the correct level in the crank case. ioo much oil will 
reach the combustion chamber and form carbon, and too low a level 






35 



























































































will prevent the contact of the connecting 
rod. This system can not be satisfactorily 
applied to the two cycle engine as too much 
oil is carried thru the by-pass into the com¬ 
bustion chamber. 

For general gas engine practice the 
FORCE FEED LUBRICATOR forms an 
ideal system. By it the oil is pumped thru 
the oil tubes to the various bearings. It is 
positively driven by belt or gear from the 
engine and starts and stops with the engine. 
Each outlet may be individually regulated so 
that just the exact amount of oil necessary is 
fed. Its pressure is sufficient to prevent 
clogging of the tubes if reasonably clean oil is 
used, and the only attention it requires is to 
be kept filled. Force feed lubricators can 
now be had which require no ball or spring 
checks for the pumps, thus obviating trouble 
arising from dirt or thick oil preventing the 



checks closing. 


\ 





Splash Oiling System 

THE CIRCULATING SYS¬ 
TEM OF LUBRICATION has 
proven very satisfactory in auto¬ 
mobile practice and in large sta¬ 
tionary plants. It consists in 
pumping the oil from a reservoir 
to the bearing surfaces, from 
which it drops into the crank¬ 
case and flows back to the reser¬ 
voir to be used again. This sys¬ 
tem is economical in operation 
and like the force 
feed system, delivers 
the oil to the bearings 
under pressure. This g 


Mechanical Force Feed 
Oiling System 

system, like the splash, is not so easily applied 
to the two cycle engine on account of the 
crankcase being used for base compression. 

OILING THRU THE FUEL by mixing 
oil with the gasoline in proper proportions is 
the most positive, economical and 
cleanest method of lubrication; but it is 
applicable only to the two cycle engine. 

As the four cycle takes its fuel charge 
directly into the combustion chamber 
the particles of oil in the gasoline vapor 
would have no opportunity to reach 
the bearings. Circulating Oiling System 

By thoroughly mixing the oil with the gasoline 
when putting it into the tank it is drawn into the 
engine with the gasoline vapor. The oil does not vaporize 



36 





































































































but is broken up into small particles and car¬ 
ried with the gasoline vapor to every interior 
surface of the engine. On taking apart an 


engine after running with this 
method of lubricating, a film of 
oil will be found spread uni¬ 
formly on every surface. 

Under this system the engine 
is entirely unencumbered with 
lubricators of any description, 
except where grease cups are 
used on the main shaft bearings. 
No adjustments are required, no 
oil drips about the engine, there 
is nothing to be turned on or off as 
the oil starts and stops with the 
flow of fuel, no filling is necessary 
except when gasoline is taken, no 
watching of sight feeds or tank 
gauges is required and the rate 
of flow is not affected by the cold, 
the amount of oiling increases ii 


Oil 

Entering 
with Fuel 

As the engine speed is increased 
proportion. 


Mixing Oil and Gasoline 



Careful experiments have shown satisfactory results with a 


mixture varying 


all 


way 


Oil Carried 
to Cylinder 
Walls 


from one pint of oil to five gal¬ 
lons of gasoline to one pint to 
twelve gallons. With a new en¬ 
gine it is safe to use one full pint 
to five gallons, which may later 
be cut to one pint to eight 
gallons. 

The mixture if properly 
made does not separate under 
ordinary cold temperature. The 
oil and gasoline should never be 
poured into the tank separately; 
they may be stirred together in 
an open tank before pouring or 
both poured at the same time, 
the oil so slowly that some of it 
mixes with every bit of gasoline 
while pouring. 

No matter what method of 
lubrication is used good oil is 
as essential with one system as 
with another. 


37 




































CHAPTER V. 


Cooling 

As the greatest temperature of an explosion is about 3500 
degrees it is evident that no lubricant could withstand this heat, 
so some means of cooling the cylinder walls must be provided. 
This is accomplished with either air or water. 

THE AIR COOLED ENGINE has been 
operated most successfully in size up to 
about 4" bore; above this point the radiating 
surface does not increase in proportion to 
the increase in heating surface and conse¬ 
quently the large air cooled engines have not 
been entirely successful. 

The cylinder of an air cooled engine is 
cast with many flanges, either vertical or 
horizontal, so as to present a large radiating 
surface to the air. A forced draft is circu- 
lated about the cylinder by belted or Air Cooled Cy lmd er 
geared fans and by casting the fly wheel spokes fan shape. 

THE WATER COOLED ENGINE 




the side of the tank near the bottom. The hose or pipe connections 
must be from the outlet in the tank to the lowest point in the water 


38 











































jacket and from the highest 
point in the jacket to the 
inlet near the top of tank. 

The level of water in the 
tank must be kept above the 
inlet connection. Thus as 
the water in the jacket heats 
it rises and flows into the 
top of the tank, the cold 
water from the bottom of the 
tank takes its place in the 
jacket. The hot water at 
the top of the tank, cooling, 
gradually sinks to the bottom 
and the circulation continues 
automatically. 

This system is used on 
most stationary and many Thermo-Syphon Cooling System 

automobile engines. 

An engine will operate at its highest efficiency when hot, 
provided of course it is not so hot as to burn out the lubricant. 
It is perfectly safe to run with the water leaving the cylinder at the 
boiling point, 212 degrees; but as it is hard to tell how much hotter 
than boiling the water really is it is best to have sufficient circulation 
to keep the temperature below the boiling point. 

Clogged water passages offer danger of over-heating and damag¬ 
ing an engine, so no foreign matter should be allowed to get into the 
tank or circulating system. In case of marine engines a water 
strainer should be. used near the engine intake, and frequently 
cleaned. 



All water connections should be tight. If there is a leak be¬ 
tween the pump and the intake, air will be drawn in instead of water. 

If hose is used in the intake system it should be heavy. The 
suction of the pump may cause a light hose to draw together and 
stop the circulation. 

A broken gasket in a rotary pump will have the same effect as 
a leaky intake pipe. 

Dirt drawn into a rotary pump may shear the pin holding the 
gear to the shaft and prevent operation; in a plunger pump it 
may clog in a check valve and also stop circulation. 

At the first frost the jacket of a water cooled marine or stationary 
engine should be drained every time after running. The thin 
film of water in the jacket freezes very easily and a cracked cylinder 
results. 

Where a stationary or automobile engine is run in freezing 
weather a solution of 15% alcohol, 15% glycerine, 70% water can 
be used for a temperature not lower than 5 degrees below zero. 
For a temperature not lower than 15 degrees below zero the alcohol 
and glycerine should each be increased to 17%. 


















CHAPTER VI. 

Installation 

Installation is as important to the successful operation of an 
engine as the carburetor or ignition system and should be as care¬ 
fully considered. Every owner should have a knowledge of proper 
installation methods. 

FOUNDATION is the first factor to be considered. Whether 
marine, stationary or portable every engine should have a firm, 
solid foundation, one that will absorb vibration. 

A STATIONARY ENGINE of six or more horsepower should 
have a permanent foundation. This can best be made by digging 
a pit about two feet deep where the engine is to stand. Make a 
wooden template, corresponding to the bottom of the engine base, with 
holes bored in it exactly corresponding to the foundation bolt holes in 
the base. The foundation bolts, long enough to reach from tli£ 
bottom of the pit to three or four inches above the surface should be 
run thru the holes in the template, which is then placed across the 

top of the pit. Fil’ 
the pit with brokei 
rocks, bricks ano 
concrete, four parts 
sand to one part 
cement thoroughly 
mixed with plenty of 
water. Salt water 
sand can p^t be used 
—a littf crushed 
stone mm vith the 
concrete is advisable. 
When the cement has 
dried, the wooden 
template which has 
held the bolts in 
place may be re¬ 
moved and oak 
planks two inches 
thick should be plac¬ 
ed on top, holes being bored to allow the foundation bolts to 
protrude thru. The wood acts as a cushion, absorbing vibration 
and protecting the engine from shock. The engine may then be 
set in place, the threaded ends of the foundation bolts entering 
thru their holes in the base and securely fastened with nuts. 

The piping and wiring of a stationary engine is simply a matter 
of placing where the most convenient. It is never advisable to 
pipe the exhaust into a chimney or out against a wall, as the con¬ 
tinued force of the explosions will gradually wear thru the brick 
and mortar; neither should it be piped into a sewer. The general 
instructions for piping and wiring a marine motor may be applied 
to a stationary. 



|40 






































Marine Engine Foundation 

The foundation timbers for a marine engine should be oak or 
yellow pine. Those running lengthwise should be as long as the 
shape of the boat will allow, crossing as many ribs as possible, the 
cross timbers of the foundation should extend over as much of the 
beam as possible. The whole engine bed should be securely bolted 



41 






















































































to the boat, by brass or galvanized bolts thru the keel and ribs, the 
bolts being put thru from the outside and fastened with nuts on the 
inside. By making the foundation long and fastening it securely 
the engine vibration will be distributed over the entire boat and 
scarcely felt; the smaller the engine bed the more pronounced will 
each impulse be felt thru the boat. 

The engine is usually fastened to the bed with lag screws. A 
better way is to bore the timbers and run bolts thru from the bottom 
so as to line up with the bolt holes in engine base, and secure with 
nuts. These bolts need not come thru the bottom of the boat, 
merely thru the foundation timbers. 

All bolts used in such installation should be of the carriage type, 
square under the round head, so as not to turn when tightening or 
loosening the nuts. 

Where lag screws are used the engine should be moved from its 
foundation as seldom as possible as the screw holes in the wood will 
soon wear large. By using bolts the engine may be taken off and 
replaced as often as desired without injury to the foundation. 

Alignment 

Lining up the engine and propeller shafts is the next step in 
installation. Be sure that the propeller shaft is central in the 
bore of the shaft log, then adjust the engine on the foundation so 
that the two shafts are in perfect alignment; this should be done by 
shaving down the foundation timbers or shimming up under the 



Installation of Marine Equipment 


base, as needed. It is well to leave the timbers a trifle high as it 
makes a better job to plane them to the proper level than to shim 
up. 

To make certain of proper alignment bring the two halves of the 
coupling together, tear a business card into four pieces and place 
a piece between the half couplings at top, bottom and either side; 
each piece should be held firmly. If the top pinches and the bottom 
pasteboard is loose the forward end of the engine bed is too high, 
etc. 

Never spring the shaft up, down or sideways to get the couplings 
to register; they should go together with perfect ease. 

When coupled up to the propeller shaft the engine should turn 
over by hand as easily as it did before coupling up. 


42 















































When the engine base is finally drawn down tight to the bed 
be sure that the bed timbers are perfectly smooth, drawing down 
on an uneven surface may crack the base. 

In planning the installation arrange to set the engine as level 
as possible and still keep the propeller wheel at least three inches 
under water. A universal joint may be used between the engine 
and the propeller shaft, and the engine set absolutely level. 




Universal Joint 

The engine fly wheel should clear the bottom of the boat by at 
least one inch if possible. 

If possible do not pitch the propeller shaft more than one inch 
to the foot. The greater the pitch the more the propeller is pushing 
up instead of ahead. 

If a newly installed engine will not start, or seems to lack power, 
uncouple the shaft and try it. The trouble may be a bind in the 

Where a clutch is used extra care in alignment should be 
exercised as there are three instead of two shafts to center. 



Stuffing Box 

The stuffing box, which is usually a combined stern bearing 
stuffing box to be used outside, should be securely 
fastened to the stern post with bronze or galvan¬ 
ized lag screws or bolts. A neat installation is to 
recess the stern post about 3-4 to the exact size 
and shape of the box. Hanger bolts (with long 
wood screw thread on one end and about one inch 
machine thread on the other) are better than lag 
screws. They become a permanent part of the 
boat and the bearing may be removed without 
enlarging the screw holes in the wood. 

Give the stern post where the bearing is to fasten a thick coating 
of white lead, or use a gasket thickly covered with white lead. 

Before launching be sure the stuffing box is packed and the 
packing nut screwed up tight. Candle wicking 
soaked in oil is good packing for a small stuffing 
box, for larger sizes regular square hemp packing 
or rawhide is better. 

Sometimes a plain stern bearing is used out¬ 
side and stuffing box inside. This is not really 
necessary as a good outside stuffing box properly 
^tem Bearing packed should not need attention during an entire 


Combination 
Stern Bearing 
Stuffing Box 



43 














season. When this installation is used double care should be taken 
in lining the shaft so that it does not bind.in either bearing. 

Where a long propeller shaft is used it is advisable to place one 
or more intermediate bearings between the coupling and the stern 
to prevent the shaft from kinking or whipping. Ordinary pillow 
blocks may be used for this.. 


Propeller 

Design of hull, power and speed of engine and diameter and pitch 
of propeller should be considered jointly and adapted each to the 
others, in order to obtain the greatest efficiency. 

The principle of a propeller is that of a screw—it advances a cer¬ 
tain distance at each revolution. The number of inches advanced 
per revolution, provided there were no slip, is designated as the 
pitch—thus, with no slip, a 20 inch pitch propeller would advance 
thru the water 20 inches with each revolution. 

Water, however, gives way to a certain extent to the revolving 
blades, and the actual travel of the wheel is less than the theoretical. 
The difference between actual and theoretical travel is called the 
slip; the percentage of slip is obtained^by dividing the slip by the 
theoretical speed of the propeller. 

The ratio of pitch to diameter is called pitch ratio. Pitch ratios 
of from .8 to 1.5 are used on work and pleasure boat propellers while 
for speed boat the pitch ratio will sometimes be as great as 2.0. 

The resistance offered by the water to a heavy, deep draft hull 
is so great that a propeller of high pitch would only churn the water, 
and the slip would be excessive. The light, shallow draft boat 
meets much less resistance and is able to advance with a high pitch 
wheel with a much smaller percentage of slip. 

Engine manufacturers usually furnish a wheel that is generally 
adapted to the power and speed of the engine. Obtaining the very 
greatest propeller efficiency is generally a matter of actually trying 
propellers of different diameters and pitch. 

The question of two or three bladed propellers is largely a matter 
of personal choice, altho the three bladed wheel is more generally 
used and is considered better balanced. Two bladed propellers 
are used on auxiliaries so that the blades may remain perpendicu¬ 
lar, back of the deadwood, when sailing, thus offering no resistance. 
Two bladed wheels sometimes give better results at very high speeds 
than three bladed, as there is less chance of “churning.” For boats 
with wide deadwoods the three bladed wheel is preferable as two 
blades are at all times in “live” water. 

A true screw propeller is one in which the pitch is tfre same 
from hub to end of blade. 

The diameter of any propeller is twice the distance from the 
center of the hub to the end of a blade. 

Vibration may result from a propeller that is not bored true, 
that is not properly balanced, or in which the pitch of the blades vary. 

Excessive “squatting” of the stern may sometimes be overcome 
by using a wheel of less pitch or less blade area. 


44 


A propeller too small in diameter or 
pitch is apt to “churn;” one of too great 
diameter or pitch will hold down the speed 
of the engine and consequently decrease its 
power. 



Propellers are either Right Hand or Left 
Hand. An engine which turns toward the 
left as one faces the fly wheel looking aft is 
a Left Hand Engine and requires a Right 
Hand Wheel; a Right Hand Engine turns 
toward the right as one faces the fly wheel 
looking aft and requires a Left Hand Wheel. 
The crowning, or convex side of the propeller blades should 
always face the boat, the flat working side facing aft. 



Reversible Propeller 

Reversible propellers are so made that the angle of the blades 
may be reversed and the boat pulled backward, altho the propeller 
is still revolving in the same direction. To accomplish this the 
blades and hub can not be an integral casting, but the blades must 
be fitted into the hub so that their pitch may be shifted, and some 
device provided for shifting. This is usually accomplished by a 
solid shaft keyed to the hub encased in a tube connected with the 
blades. 



The Reversible Propeller has the advantage of permitting the 
operator to set the blades at about any pitch, either forward or back, 
thus giving an excellent control of boat speed. 


Reverse Gear 

Reverse gears are used with the large majority of marine engines, 
particularly with those of 6 horsepower or more. A reverse gear 
affords practically the same control of a motor boat that one 
has of a motor car—the engine may be started and run without 
putting the boat under way, the boat may be started at once under 
full power either forward or back, immediate change from full 
speed ahead to full power reverse, or vice versa, may be made. 

A reverse gear usually consists of two friction clutches and a 
system of gears. When the clutch lever is in neutral the engine 


45 



















$ 


runs free without load, the propeller shaft does not turn, the gears 
are revolved idle by the main drive gear—there is no load on them 
and consequently no wear. On the advance one friction clutch is 
brought into play which clamps the entire gear together, forming 
one solid coupling, the propeller shaft is turned in the same direc¬ 
tion with the engine, the gears do not revolve on their shafts and there 
is no wear. On the reverse the outer friction clutch brings the gears 
into action and the propeller shaft is revolved in the opposite direc¬ 
tion. 

The friction surfaces should be ample and all material the best, 
small parts and gears should be of heat treated steel. Easy adjust¬ 
ment of the friction bands should be provided. 

The clutch, either on the advance or reverse, should be let in 
easily so that the load is picked up without a jerk and sudden 
strain. 

The gears of a marine reverse gear are always in mesh. 

A heavy transmission oil or a mixture of cup grease and lubri¬ 
cating oil should be used for lubrication, and the gear case should 
always contain a level sufficient for the gears to dip in. 

A ONE WAY CLUTCH is sometimes used on speed boats to cut 
down weight, altho most racing rules now require some means of 
reversing the boat. The clutch has no gears and is simply a friction 
clutch which allows the motor to be started and to run idle without 
turning the propeller shaft. By engaging the friction band the 
engine and propeller shaft are locked as one solid shaft. 

Thrust Bearings 

Somewhere in the transmission a bearing must be provided to 
take up the lateral thrust of the propeller. Two thrust bearings 
are usually incorporated in the engine itself to relieve the thrust 
strain both on forward and reverse. Reversing clutches also con¬ 
tain thrust bearings to protect the mechanism from this lateral strain. 

Exhaust Piping 

Black iron pipe is all right for the exhaust. It should be as 
large as the engine exhaust connection and as straight and direct 
as possible. Sharp turns should be avoided, use 45 degree elbows 
wherever possible. Every sharp turn offers resistance and causes 
back pressure. 



46 









$,;It is well to coat "exhaust pipe 
threads with graphite so that they 
may be more easily taken apartjjf 
necessary. 

When water from the engine 
is put into the exhaust the pipe 
should have a gradual drain from 
the engine to the terminal, nowhere 
should a pocket or trap be formed 
unless a separate drain connection 
is made at a point above the water 
line. Neither should the piping 
at any point be higher than the 
exhaust port of the engine. 

The muffler may be placed any¬ 
where in the exhaust line. 


Submerged Exhaust 

Where an underwater exhaust 
is used the terminal should never 
be more than four inches below 
the water line. If the exhaust 
port of the engine is below the 
water line of the boat the exhaust 
pipe should be elevated consider¬ 
ably in the form of a gooseneck 
as shown. 

A satisfactory under water ex¬ 
haust system consists in bringing 
the pipe out the stern with its 
lower edge right on the water line; 
as the boat starts the stern will 
settle enough to submerge it. 

The accompanying cut shows the 
proper arrangement of piping for 
submerged exhaust. “A” is an ex¬ 
pansion chamber placed near the 
cylinder of the engine. Expansion 
chamber “A” can be located under 
back deck in the horizontal pipe 
line ahead of the 45° Ell. “E.” In 
this case connect overflow “B” 
from engine into exhaust pipe 5 or 
6 inches below exhaust outlet of en¬ 
gine. “B” is the overflow water 
from the engine piped into the top 
of chamber. 



47 

















































“C” is the outlet for water to drain overboard above the water 
line. You will notice that the exhaust pipe rises in the stern of the 
boat at “E” to a height that will positively prevent water enter¬ 
ing from “F” and lodging in the pipe in any kind of emergency. 
“F” forms a terminal for the exhaust pipe. 

So far this description of the submerged exhaust consists en¬ 
tirely of a home made product, such as can be easily gotten in any 
community. However, you can substitute any of the ‘‘submerged 
exhaust” devices for “F.” The exhaust outlet for “F” rtiust not 
be more than two inches below the load water line. The stern is 
the best place for the exhaust outlet, because when you are backing 
your boat, or when your boat is standing at dock, the stern is 
naturally higher than when the boat is running ahead, and will 
prevent back pressure at the time of starting or when backing up. 

IMPORTANT 

It is very important that every part of the exhaust pipe, ex¬ 
pansion chamber and drain are placed above the water line, to 
prevent water from lodging in the exhaust system and causing you 
trouble when you wish to start the engine. 


Muffler 

The expanding exhaust gas as it bursts from the exhaust pipe 
causes a report like that of a gun; a muffler is therefore used to 
afford the gas a better opportunity to cool and contract to 
atmospheric pressure. 

The Marine Muffler is usually designed to allow at least a part 
of the circulating water to pass thru it, thus materially aiding in 

reducing the exhaust pressure and at 
the same time keeping the piping cool. 

In running water thru the exhaust 
care must be taken in the piping that 
the water is thoroughly drained from 
pipe and muffler. 

Stationary and automobile engines 
are not piped to run the water thru 
the exhaust but depend on air radiation and the baffle plates 
in the muffler to cool and break up the hot gas and muffle the 
exhaust. 



Marine Muffler 


48 
























Water Piping 


Water pipes should be brass or galvanized iron. The line from 
the inlet to the pump must be as short and direct as possible. 

A scoop on the outside of the boat is advisable; its opening 
should always face toward the bow of the boat. 



/Ibore water/me 


G/obe Vo/res. 


Water Jtrainer . 


Quf/ef be/oe wafer/tne jrertfjng 
run rerers/no - 


'/ i Afust be a t teas / J t/rcbea aboye /pad 
water Z/ne /b irrsure perfect drainag e. 


The intake terminal thru the boat should be screwed up firmly, 
with leather washers coated thickly with white lead both inside and 
outside the planking. 

A sea cock may be used just inside the intake to regulate the 
amount of water. This however is dangerous because one may 
forget to open it or it may accidentally become closed, and the 
restriction or absence of water damage the engine. 


.Water Discharge 

Water Valve ^ ___ , 

Water Hose^ 

Connections \ 
with Nipples 


Water Intake 


-Water Hose 
-Hose Clamp 
-Pipe Nipple 
Sea cock 



Water Scoop. 


Water Connections 


49 
























































































A good strainer should be used between the intake and the 
pump. 

A three-way valve is sometimes placed in the water intake and 
a hose connection made to the bilge so that the bilge may be pumped 
by the engine. This has the danger of running 
greasy water thru the engine jacket, and also one may 
forget to turn back to the main line 
when the bilge is pumped. It is 
convenient but must be watched. 

The water outlet may be piped 
directly overboard wherever con- 



Pipe Terminal 



Water Scoop 

venient; or it may be piped into the exhaust, under conditions of 
installation previously described; or a regulating valve may be used 
and connections made both overboard and into the exhaust so that 
it may be directed either way or divided, part flowing into the 
exhaust and part overboard. 


Rubber hose may be used in both water intake and outlet lines, 
but hose clamps should be used and firmly drawn up. A short 
section of steam hose may be used in the exhaust line, near the 
terminal, provided part of the water is run thru the exhaust. The 
use of sections of hose will take up vibration between the engine and 
the hull. 


Gasoline Tank and Piping 

The gasoline tank should be strongly constructed of copper or 
galvanized iron. A large tank should have splash partitions to 
prevent the gasoline as a body rolling during a heavy sea. A cyl¬ 
indrical tank is stronger than any other shape. 

Before placing the tank, it, and all connections and piping, 
should be inspected to see that they are perfectly clean and contain 
no water. 

The tank should be so located that the bottom will be higher 
than the float level of the carburetor at all times, allowance must 
be made for the weight of a full boat load, the distribution of weight 
and the rolling and pitching in a sea. 

The tank inlet should be large, at least 1" pipe is advisable, 
and capped so that no water can get in. 

A vent should be provided at the top of the tank, so that air 
may get in as the gasoline is being used, otherwise a vacuum is 


50 






Gasoline Connections 


formed and the flow stopped. The vent may be a separate pipe 
connection in the tank into which a relief cock is screwed; the cock 
may be turned off when the engine is not running to prevent evapora¬ 
tion. A small hole, 1-32" is enough, may be drilled in the top of 
the filler pipe just under the cap for a vent. 

A shut off cock should be placed at the tank outlet, then a union, 
then the gasoline pipe with another union and shut-off 
cock at the carburetor. The use of the two cocks and 
unions will allow the piping to be taken out at any 
time for cleaning or repairs without disturbing either 
the tank or carburetor. A good strainer should be 
connected up in the line right at the carburetor. 

It is always advisable when laying up for a few hours to shut 
off both cocks. In this way there is no danger of a leaky pipe flood¬ 
ing the bilge with gasoline, and the carburetor needle valve always 
remains in constant adjustment.. 

If any work is done on the boat after the tank has been placed 
great care should be taken that no sawdust or shavings find their 
way into the tank. 

The tank is sometimes placed lower than the carburetor and air 
pressure used to force the gasoline. This system is not advisable, 
it puts extra pressure on tank, pipe and connections, the pressure 
is rarely constant so that frequent change of carburetor adjustment 
is required, nor is it automatic. 

The gasoline pipe may be annealed copper tubing, which is best 
except for large engines, medium weight lead pipe or brass pipe. 
It should never be smaller than standard 34 " outside diameter 
tubing; there is less danger of clogging up if larger is used. 

If copper tubing is used make one coil in the line at the carbure¬ 
tor to take up vibration, if other pipe is used put a coil of copper 
tubing in the line at the carburetor for the same purpose. 

All gasoline connections should be made up tightly, using shellac 
on the threads. Solder-unions are best to use. The pipe should 
be securely fastened to the boat with cleats to prevent cracking from 
vibration, and it is best to keep it above the floor so that a leak 
may be readily noticed> 

Remember there is no danger from the gasoline so long as it 
or the vapor does not leak. 



51 

























CHAPTER VII. 


Wiring 

The various types of ignition systems require various arrange¬ 
ments of wiring, and the manufacturer’s directions should be 
closely followed. There are a few principles however that apply 
to the installation of practically any system. 

Follow the manufacturer’s diagram. 

Use good wire intended for ignition service. 

The heavily insulated wire carries the high tension current and 
joins the spark plug and the secondary connection on the coil or 
magneto. The smaller wire carries the low tension current and 
connects batteries, commutator, ground and primary coil connec¬ 
tions. 

THE LOCATION OF COIL AND BATTERIES in relation to 
the engine should be so that all connections are as short as possible; 
the longer the wires the greater voltage consumed in forcing the 
current thru them. There is less danger of short circuiting and 
leakage in short than long wires. These facts make apparent the 
value of a coil or magneto attached to the engine. 

Both coil and batteries should be placed where they will be 
free from rain, spray or the collection of moisture, at the same time 
they must not be so close to the exhaust as to melt the insulation. 

Locate the switch where it will not be accidentally opened or 
closed by brushing against it. 

Keep all parts of the ignition system free from water and oil, 
except the bearings of the commutator and magneto which are 
intended to be oiled slightly. 

Do not run the wires under the floor of the boat—keep them 
from coming in contact with metal surfaces—fasten with cleats 
rather than staples and be sure that all connections are tight. 

In connecting up a set of batteries always connect from carbon 
to zinc; that is, from the center connection of one cell to the 
outside connection of the next. 


52 



A*if.r7V 7Wa .5igT-.-s o*-/^*n~£K*i£n 

























































































































































✓ 




54 











































































































































Fur Wheel. 






# 


55 


























































































































Bosch DU 1 Ion m on System 



Wiring for One Cylinder Independent Type High Tension Magneto 


BoschDU2 Ignition System 



Wiring for Two Cylinders Independent Type High Tension Magneto 

56 











































Bosch DU3 ignition Syste m 



Wiring for’Three Cylinders Independent Type High Tension Magneto 


bosch DU3 Dual ignition System 



Bosch DU3 Dual Mac/*£ ro 

NO. ftS^SidARELow TEHSionC/KbUS 


Wiring for Three Cylinders Dual Type High Tension Magneto 

57 
























































































/y/oyra/r? of nr/r/hy 0/7 00 e cy/. 
w/M fo/fer/es osr</ /Voy/reAp /a com^/oa/zo/?. 



/J/cyrc/77 of *y/r//7y 0/7 Two cy/. 

sy///7 /c/fec/es A?oy//efo /> c<?/??/>//pa.y 0 / 7 . 


58 





























































































/*7y W/iee/. 


0/0f/’0/77 efi/K/fi/fif e/7 /fire e cy/. 

ry//fi fi<77/e/-/es a?*/ /%?y/7e/o //? ca/nfi//7<7/>0/7. 




9 


























































































































































































CHAPTER VIII. 


Operation 

It is a good plan before starting the motor for the first time to 
put enough oil in the crankcase so that the connecting rod will 
dip into it, also pour a little into each cylinder thru the spark plug 
hole. This will not last long but will insure sufficient lubrication 
until the regular oiling system can supply enough. 

Be sure the spark plug points are the proper distance apart and 
that all wiring connections are tight. 

STARTING. Turn on the gasoline valves between tank and 
carburetor and prime carburetor. Retard the spark and close 
throttle to about one quarter open and give the carburetor needle 
valve about one turn. Rock the fly wheel back and forth a few 
times to get a charge into the engine. Then throw in the switch 
and throw the fly wheel sharply up against compression in the 
opposite direction from which the motor runs. 

Remember that when starting direct on high tension magneto 
the switch must be opened instead of closed for starting and running 
and that the fly wheel must be thrown entirely over compression 
in the direction in which the motor runs. 

It may be necessary particularly in cold weather to prime the 
engine by filling the priming cup with gasoline and rocking the 
fly wheel back and forth until the cup is empty and some air has also 
been drawn in. Better have the current off when priming. 

Too much priming and cranking or too rich a mixture will 
flood the engine, and it may be necessary in a two cycle engine to 
open the priming cock and drain cock in base and rock the fly wheel 
until the excess gasoline is forced out. 

Continual cranking will not start a motor—if it fails to start 
easily some condition of installation or operation is wrong or 
has been forgotten. 

In. stopping it is advisable to open the throttle just before 
throwing off the switch so as to stop with a fresh fuel charge in the 
cylinder. 


Engine Troubles 

HARD OR IMPOSSIBLE TO START may result from: 


1. Loose or broken wire connections 

2. Batteries wired wrong 

3. Batteries run down 

4. Open switch 

5. Dirty or broken spark plug 

6. Poor coil adjustment 

7. Short circuit in timer 

8. Gasoline shut off 

9. Poor gasoline mixture 


10. Water in gasoline 

11. Gasoline pipe clogged with dirt 

12. Engine flooded 

13. Broken or leaky check valve (in 

two-cycle) 

14. Cylinder dry from lack of oil 

15. Poor compression 

16. Leak from water jacket into 

cylinders 


60 


MISSING—IRREGULAR FIRING—may be caused by: 


1, 

Poor carburetor adjustment 

7. 

Poor adjustment of spark coil 

2. 

Water in gasoline 

8. 

Sooted or broken spark plug 

3. 

Partly clogged gasoline feed 

9. 

Broken insulation on wiring 

4. 

Weak batteries 

10. 

Spark plug short circuited by 

5. 

Loose or broken wire connections 


water 

6. 

Poor connection in timer 



REGULAR BUT WEAK EXPLOSIONS may be due to: 

l. 

Poor compression 

4. 

Pitted or poorly adjusted vibrator 

2. 

Lack of lubrication 


contact points 

3. 

Back pressure on exhaust 

5. 

Tight bearing 

SUDDEN STOPPING OF THE 

ENGINE may be the result of: 

l. 

Broken wire or loose terminal 

4. 

Broken spark plug 

2. 

Accidental disengaging of switch 

5. 

Shearing of commutator gear pin 

3. 

Sticking of coil vibrator 

6. 

No gasoline 

GRADUALLY SLOWING DOWN 

may be caused by: 

l. 

Poor mixture 

9. 

Weak commutator contact springs 

2. 

Air vent in tank closed 

10. 

Lost motion in commutator con¬ 

3. 

Crankcase leak 


trol rods 

4. 

Dirt in carburetor 

11. 

Weak batteries 

5. 

Low fuel level in tank 

12. 

Overheated cylinder or shaft 

Kpo fi ti ct 

6. 

Gasoline valve partly closed 

13. 

Dcciring 

Check valve broken (in two- 

7. 

Dirty spark plugs 


cycle) 

8. 

Commutator loose on shaft 


• 

EXPLOSIONS IN THE MUFFLER 

will follow: 

l. 

Cylinder missing fire 

4. 

Over retarded spark 

2. 

Mixture too weak to ignite 

5. 

Exhaust valve failing to seat (in 

3. 

Weak spark 


four-cycle) 


EXPLOSION IN CRANKCASE 
due to: 

1. Weak mixture 

2. Throttling too low 

3. Open throttle and retarded spark 


OR CARBURETOR may be 

4. Failure of inlet valve to seat (in 
four-cycle) 


KNOCKING or POUNDING 

1. Loose fly wheel 

2. Loose connecting rod bearing 

3. Cylinder loose on crank case 

4. Worn main bearings 

5. Broken piston ring 


IN ENGINE may be caused by: 

6. Pre-ignition due to carbon in 

cylinder, lack of oil or water 

7. Spark too far advanced 

8. Mixture too rich 

9. Overloaded motor (Propeller too 

large) 


HARD IN TURNING OVER may be due to: 


1 . 

Accumulation of gummy oil and 

4. 

Tight bearings 


dirt in cylinder 

5. 

Overheated cylinder 

2. 

Lack of oil 

6. 

Bind in shaft 

3. 

Rusty or broken piston rings 

7. 

Clutch engaged 


It will be observed from the foregoing list of troubles and their 
possible causes that derangement of the carburetor or ignition system 
may apply either directly or indirectly to nearly every condition. 
It is also evident that imperfect lubrication or water circulation 
may result in many of the troubles mentioned. It may also be 
noted that very few of these difficulties result from defects in the 
motor or its standard equipment. The conclusion must be that it 
is up to the operator to know that the installation is right and that 
all adjustments are right. 

It may be noted that the same cause is given for several different 
effects—for instance, poor mixture or imperfect adjustment may 
result in hard starting, missing, slowing down, muffler and crank¬ 
case explosions and knocking. Remember that there are different 
degrees of all conditions and that results will therefore differ. 
Experience will usually enable one to know what causes an abnor¬ 
mal condition. 


Pointers 

Dirt in the gasoline may cause flooding by holding open the 
carburetor float valve, or it may cut down or shut off entirely the 
gasoline by sticking in the needle valve. 

When a two cycle engine explodes every other revolution (four 
cycles) the engine is flooded. Shut down the needle valve gradually 
until the firing becomes regular. 

A sand hole or crack in engine base, leaky base or inlet gaskets 
or weak spring on check valve results in a lean mixture and will 
make a two-cycle motor hard to start and detract from its power. 

It is always advisable after running a new engine for the first 
time to go carefully over all cap screws and nuts with a wrench and 
tighten same up as these may have become loosened during ship¬ 
ment and installation. A large wrench should never be used nor 
should an undue strain be put upon nuts or cap screws as they are 
easily twisted off. 

Own an ammeter and test your dry cells when you buy them 
and frequently after they have been in use. 

Grease causes the rubber insulation of wires to deteriorate. 
Keep them out of the oil and grease. 


62 


Where an oiler is used feed about 40 drops a minute for the first 
200 miles run, then gradually cut to 30 drops or even less until 
there is just a faint blue smoke at the exhaust. 

Control your speed as much as possible by the throttle. After 
starting open throttle and then advance spark. When the engine 
is subjected to a heavy load retard spark slightly and then slowly 
advance it as engine speed picks up. in reducing speed close 
the throttle before retarding spark. 

If a motor has been standing a long time pour a half cup of 
kerosene and oil thru the spark plug hole and crank the motor over 
several times. Drain this mixture from base before starting. If an 
engine turns over hard this operation will frequently limber it up. 

A half cup of kerosene poured into the cylinder once a month, 
worked thru the engine by cranking over several times and then 
drained from the base will increase the power and smoothness of 
operation, it removes the carbon and gummy oil and keeps the 
rings free. 

Occasionally reverse the current thru the coil by interchanging 
the ground and coil connections from the batteries—it keeps the 
vibrator points in better condition. 

To properly clean a spark plug remove the core and clean all 
soot from core and inside of shell with fine emery cloth or stiff brush. 

Keep vibrator and contact screw points smooth and flat by 
occasionally dressing with very fine hie or emery cloth. 

If you use double ignition, both batteries and magneto, switch 
to batteries just before stopping so there is no chance of stalling 
the engine at low speed. 

Black smoke at the exhaust denotes too much gasoline. 

White smoke at the exhaust indicates too much oil. 

When starting a large engine by cranking over the compression 
open the relief cocks in cylinder until started. 

A good spark will often ignite a poor mixture but a poor spark 
will seldom ignite a good mixture. 

If you run your boat in muddy, sandy or shallow water dirt 
may settle in the water jacket. Take out the plug or disjoint a 
connection at a low point in the circulating system and force clear 
water back thru the jacket. 

Drain the bowl of the carburetor at frequent intervals to relieve 
it of any possible dirt or water. 


63 


A multiple cylinder engine will^often start on the spark by 
turning on switch and sharply retarding the spark control lever. 

A rich mixture is slow burning and will tend^to overheat the 
motor. 

A mixture may be rich either from^too much gasoline or too 
little air; it may be weak either from too little gasoline or too much 
air. 

On account of the increased suction in the_air .passage ofjthe car¬ 
buretor a smaller flow of gasoline is required at high speeds than at 
low. The puddle type carburetor automatically takes care of this 
condition. 

A properly adjusted coil should draw from .3 to .5 amperes. 

Two secondary wires should not be allowed to lie near each other 
for any^distance^as the live one will induce a slight current in the 
other. 

No horse^power formula can be accurate as applied to various 
makes of engines because it can not take into consideration the 
size of valves, the location and size of ports, or the general design 
and construction. 

In wiring dry cells care ^should _be taken that ^the zinc binding 
post of^one cell does not touch the zinc shell of .the next cell to 
which it is wired. This would short circuit the first cell and ruin it. 

In looking for ignition trouble if the coil vibrators buzz the 
trouble is not in the primary circuit, which includes all of the 
ignition system but the spark plug, high tension wire, ground 
wire and secondary winding of the coil. 

A loose connection may complete a circuit when the engine 
is turned over slowly, but may not connect under the vibration 
of the engine running up to speed. 

A spark may look good in the open air but still be too weak to 
ignite a charge under compression. 

Reversing Engine 

A two cycle engine may be run in either direction altho the 
manufacturer sets it to operate best in one direction. They will 
run in the opposite direction by placing the spark lever in what would 
be advance position if running in the natural direction, and rocking 
engine against the compression or cranking over. 

Two cycle motors may be reversed by throwing out the 
switch, reversing the position of the spark lever and closing the 
switch after the engine has slowed down and just before it stops. 
Practice will make anyone very proficient in this so that it may be 
done almost with certainty. It is not advisable to trust to this 
in making a landing. 

Reversing an engine is not generally recommended. It is pos¬ 
sible to spring the shaft or otherwise damage and rack the engine 
by closing the switch before the motor has slowed down sufficiently. 


64 


CHAPTERIIX. 

Overhauling and Repairing 

When an engine is to be overhauled or repaired the necessary 
tools should be at hand, then one or more boxes should be provided 
in which to place the parts so that nothing will be lost. If the en¬ 
gine is of the multiple cylinder type, the parts of each cylinder 
should be kept together. 

If the motor is to be entirely taken down all wiring, water, 
gasoline and exhaust connections should first be removed. The 
engine should then be stripped of all outside parts. 

Rusty nuts and bolts may often be started by flooding with 
kerosene and allowing to stand a few hours. A rusted exhaust pipe 
connection may be started by tapping smartly with a hammer. 
Never put undue strain with a wrench on a rusted bolt or nut, nor 
when tightening up bolts and nuts. 

In making up exhaust connections the use of graphite on the 
threads will tend to prevent the connections rusting and burning 
tight. 

If commutator shaft or cam shaft gears are removed a scratch 
should be made with file, saw or cold chisel across the teeth in mesh 
of each gear. In replacing the gears these marks should register. 

To prove the setting of the commutator remove the spark plug 
and the commutator top. By means of a screw driver or piece of 
stiff wire determine when the piston is at the top of the stroke. 
With the piston in this position and the commutator controMever 
midway between full retard and full advance, the contact point in 
commutator housing should be in connection with the center. of 
the round contact point of the commutator fibre. If the timing 
is not correct the position of the fibre contact with relation to the 
contact point of commutator housing must be changed. This may 
be easily done where the timer is only set-screwed to the shaft, 
but if it is pinned to the shaft, which is much the better construc¬ 
tion, the shaft driven gear must be set a cer¬ 
tain number of teeth one way or the other, to 
give the required distance on the commutator 
fibre. 

The commutator should be oiled frequently, 
but sparingly. Even then there will be an 
uneven wear of the brass and fibre so that it 
may become necessary to put the fibre in a 
lathe and take a fine cut from the outside. 

This will make it as good as new. If this repair 
is impossible get a new fibre from the factory. 

To remove a piston ring start a strip of 
heavy tin or broken hack saw blade between 
ring and piston at the slot and work it around 
the piston until opposite the slot, bridging the 
ring groove. Then start a strip on each side of 
this and work them carefully back half way to 
the slot. The ring is then free except the slotted ends and these 
may be pried up one at a time and the ring slipped off. 

65 



Removing Piston 
Rings 












A middle ring may easily be slipped over an outside ring groove 
by bridging the groove with the thin metal strips. 

In placing new rings in an engine each ring should first be 
shoved into the cylinder to make certain it has been slotted out 
enough. The slotted ends should not meet by from eight to fifteen 
one-thousandths of an inch, thus allowing for expansion from 
heat when running. 

Also try the ring for width by inserting it in its groove in the 
piston (without slipping it over the piston) and roll it around its 
circumference. It should fit snugly but still slide in and out easily. 

If it is necessary to file the slot or the edge of a ring lay it on a 
block of wood and drive brads close around it both on the inside 
and outside circumferences. This will hold the ring firmly while 
filing. If dressing down the width file only one edge. Do not use 
emery cloth. 



To grind in a valve first clean it thoroughly of carbon, apply an 
abrasive (oil and emery or oil and ground glass) and turn it back 
and forth on its seat, lifting it about every dozen times so as to dis¬ 
tribute the abrasive. A screw driver or a brace and bit may be used 
for this work. 

Where slip joint connections are used on the water piping of an 
engine care should be taken that the tubing is not slipped too far 
one way or the other so as to shut off the opening in the tee fittings. 

To make paper or asbestos gaskets place the gasket material 
over the surface to which the gasket is to fit. Hold firmly in place 
and tap around all the edges sharply with a ball-pein hammer. 
This will cut the gasket cleanly and to exact size, use the ball 
end of the hammer for stud holes. This method should never 


r 


66 




















be used on aluminum, as that metal is 
too soft. Lead and copper gaskets may 
also be made this way, but rubber or 
wire-woven gaskets should be cut with 
a knife, scissors or tin-snips. 

Shellac is much used in securing an 
oil-tight joint. It may be used between 
the smooth metal surfaces of a gear case 
and should always be used on paper or 
asbestos gaskets. 

In replacing the crank pin bushings of 
the connecting rod, the crank pin should 
first be inspected for cuts. If the pin is very slightly scored a 
strip of fine emery cloth may be used to smooth it. If the scoring 
is quite pronounced it may be smoothed up by the use of a piece 
of clothesline soaked with^oil and emery. Take a turn around 
the pin with the rope and pull first one end and then the other, 
working the rope backhand forth the length of the pin. 

In all cases^where^emery is used about an engine all parts should 
be thoroughly^cleaned before they are reassembled, otherwise the 
small particles remaining will quickly wear the bearing surfaces. 

The new bushing should be fitted tightly in the connecting rod 
and the rod and cap fitted up on the pin, after smearing the pin with 
lampblack or red lead. Turn the rod on the pin and then remove 
the rod and cap. It will be found that the lampblack will have been 
rubbed from the pin to the bushing in spots; these marked spots are 
high and should be scraped down. To get a good fit this operation 
should be repeated two or three times. The bushing should also be 
scraped around the edges. 

A connecting rod cap with the bushing should always be bolted 
to the rod in the same position, never turned end for end. 

When the crank pin bearing of the connecting rod becomes worn, 
the play can usually be taken up by removing a liner from each side 
between cap and rod. When this is done it is well to refit the bushing 
the same as fitting a new one, as described above. 

There is slight wear on the- piston pin bushings, and when worn 
they should be replaced. ... . 

There is little wear on main shaft bearings if properly lubricated. 
When worn, new bushings should be put in or the bearing babbitted. 
New shaft bearings should also be scraped to fit. # 

Never allow a loose bearing to continue without attention, it 

may result in serious damage. # 

When renewing bushings or rebabbitting be sure that all oil 
grooves and oil holes are cut in the new bearings. 

Particular care should be taken in locking connecting rod nuts 
and bolts, by wiring, lock nuts, cotter pins, or whatever method the 
manufacturer provided. 

Broken castings, cylinders, crankcases, etc., may now be repaired 
by firms in the larger cities who make a business of this work, using 
oxy-acetylene and other processes. A split water jacket, the result 
of freezing, may be repaired by dovetailing the crack with a fine 
chisel and soldering or caulking with soft copper. 

67 







CHAPTER X. 


> 


Stationary Engines 


The small gas or gasoline engine has found a world-wide market 
in hundreds of different trades and occupations—there is almost 
nothing requiring power that can not be done more easily with one 
of these engines than in any other way—there is almost no place in 
the civilized world that they can not be economically operated. 

Both two and four cycle types make satisfactory stationary 
engines either in small or large units. 

For any work where the load is constant a marine type of engine 
can be successfully used for stationary purposes; but in almost all 
stationary work the load varies so greatly that a governor is neces¬ 
sary to prevent the engine “racing” when th$ load is cut down, or 
“stalling” when it is suddenly increased. 

Two general types of governors are in use, the throttling and the 
hit-and-miss. In both cases the operating movement is usually 
obtained from the centrifugal force of weights carried either in the 
fly wheel or on a secondary shaft, the movement, of course, varying 
with the speed of the engine. 


Under the HIT-AND-MISS GOVERNOR, which is applicable 
only to four cycle engines, as the load on the engine is decreased the 
speed tends to increase, the governor holds the exhaust valve open 
and the piston simply pumps air back and 
forth thru this valve. No fresh charge of 
gas enters the cylinder while the exhaust 
valve is open. When the engine speed 
falls to normal the exhaust valve is re-^Z 
leased and explosions again occur. This 
form of governor also cuts out the spark 
while holding the exhaust open. 

It is quite evident that with the hit- 
and-miss governor the variation in speed 
considerable. The THROTTLING 


is 



VERTICAL GOVERNOR 

The movement of the 


GOVERNOR, by regulating the force of 
each explosion, instead of cutting some 
out entirely, gives a much smoother oper¬ 
ating engine and very close regulation, 
governor weights is transmitted to the throttle so that as the 
load is increased the throttle opens allowing a full charge of gas, 
as the load is lessened the throttle closes until when the engine is 
running light it takes in merely enough gas to keep it in motion. 


68 











To Find Size and Speed of Pulleys and Gears 

To find the diameter of the Driving pulley, knowing the diameter 
and speed of the Driven and the revolutions of the Driver: Multiply 
the diameter of the Driven by its revolutions, and divide the product 
by the revolutions of the Driver; the result is the diameter of the 
Driver. 

To find the diameter of the Driven pulley, knowing the revolu¬ 
tions of the Driven and the diameter and revolutions of the Driver: 
Multiply the diameter of the Driver by its revolutions and divide 
the product by the revolutions of the Driven; the result is the diameter 
of the Driven. 

To find the revolutions of the Driving Pulley, knowing the 
diameter and revolutions of the Driven and the diameter of the 
Driver: Multiply the diameter of the Driven by its revolutions and 
divide the product by the diameter of the Driver; the result is the 
revolutions of the Driver. 

To find the revolutions of the Driven pulley, knowing the dia¬ 
meter and revolutions of the Driver and the diameter of the Driven: 
Multiply the diameter of the Driver by its revolutions and divide 
the product by the diameter of the Driven; the result will be the 
revolutions of the Driven. 

In figuring gears the number of teeth should be used instead of 
diameter. 

CLUTCH PULLEYS are often used 
on a stationary engine instead of the 
standard solid pulley, so that the load 

Quarter-turn Belt may be thrown on or off without stop¬ 

ping the engine and also so that the engine may be started 
without the load. 

In stationary work the machinery to be driven is often of such 
low speed that it is necessary to transmit the power thru a 

countershaft to get the proper pulley ratio. 

Short belts wear quickly, slip and cause considerable loss of power 
in transmission. To obtain the best results the distance between 
pulley centers should be at least from six to eight times the diameter 

of the larger pulley. # ... 

The engine pulley must be perfectly in line with the pulley 

which is to receive the power. 

The exhaust piping should be as short and straight as possible 
and the exhaust gas should always be discharged out of doors. 

Governor parts should be well oiled frequently. 



69 





CHAPTER XI. 


Gas and Kerosene for Fuel 

Gas, both natural and manufactured, has long been used in 
stationary internal combustion engines. Like gasoline it requires an 
admixture with air to become combustible, the best working effect 
resulting from a mixture of from 7 to 9 parts air to one part gas. 

Gas mixing valves particularly adapted to the individual engine, 
with instructions for their attachment, may usually be obtained 
from the manufacturers. A gas bag or gasometer attached between 
the gas main and the engine is also necessary to reduce the press¬ 
ure of the gas as it comes from the main. 

For large stationary gas engines, producer plants in which the 
gas is made direct from coal are extensively used. 

A gas engine under full load will consume from 10 to 15 cubic feet 
of gas per horsepower hour. 


Kerosene 



The cheaper cost of kerosene oil in comparison with gasoline 
and the inability to obtain the latter fuel in some countries has 
lead to the development of the kerosene burning engine. About 
three times more kerosene than gasoline is refined from the 
same amount of crude oil. As the consumption of kerosene per 
horsepower hour is about the same as that of gasoline its economy 
is apparent. 

If kerosene is not thoroughly gasified it leaves a heavy deposit 
of carbon which in a short time 
prevents the successful operation 
of the engine. Heat and a high 
velocity of travel to the combus¬ 
tion chamber are necessary for the 
complete vaporization of kerosene. 

As neither is found in the usual 
gasoline carburetor a special device 
is necessary for the successful use 
of kerosene. 

A kerosene engine must be 
started on gasoline and run long 
enough to become well warmed 
up before switching to kerosene. 

A recently patented kerosene car¬ 
buretor provides separate gasoline 
connection and float chamber so 
that this may be accomplished by 
simply turning a control valve in 
the carburetor, or if desired the 

engine may be run continually on Combination Gasoline-Kerosene 
gasoline. Carburetor 


70 














Starting Kerosene Engine 

With the above type of kerosene carburetor, when starting see 
that both bowls of the carburetor are filled. Open both needle valves 
one quarter turn, next turn the transfer valve, which has an arrow 
point on it, with the head of the arrow pointing vertically, which 
does not admit either gasoline or kerosene thru the spray nozzle; 
prime the engine thru the priming cup with gasoline, start the en¬ 
gine as you would any gasoline engine, and after the first two or 
three explosions, quickly turn the transfer valve with the arrow 
pointing toward the bowl of the carburetor containing the gasoline. 
After the engine has run about one minute, quickly turn the trans¬ 
fer valve with the arrow pointing to the kerosene bowl. 

In starting, it is necessary to have the timer or commutator 
lever retarded, also have the lever controlling the butterfly valve 
in the air opening about Y%" open. Afterthe first explosion quickly 
advance the timer lever. When the engine is running on gasoline 
open the butterfly air valve about half way, when the kerosene is 
turned on have the butterfly valve wide open, which is the position 
for full speed. At no time when the load is on the engine should the 
butterfly valve be closed so that the opening is less than Y" • 

When starting if the engine floods, instead of having the butter¬ 
fly valve only Ys" open, open it up wide until the engine speeds 
up, which will thin the mixture. 

When stopping engine be sure to have the arrow set vertically 
which closes off both fuels. 

For the best results a kerosene carburetor should be especially 
designed and developed for the particular type of engine on which 
it is to be used. 

Particular attention should be paid to the ignition of a kerosene 
engine as a missed explosion means less heat to vaporize the next 
charge. 

Kerosene when properly mixed and ignited burns clean and 
does not give a vaporous, smelly exhaust, both of which are notice¬ 
able when the mixture or ignition is poor. The trouble from carbon 
deposits when using kerosene usually results from not allowing 
the engine to heat up sufficiently before shifting from gasoline to 
kerosene. 

Kerosene can not be successfully used with a high compression 
engine, but the average gasoline engine is now designed with a com¬ 
pression not too high for kerosene. 

DISTILLATE AND ALCOHOL have both been used thru 
gasoline carburetors altho more heat is required for vaporization 
than with gasoline. To operate on alcohol requires a higher com¬ 
pression than gasoline, and because of requiring heat it is necessary 
to start the engine on gasoline. 


71 


X 



V 






JUL -.1 I9W 









































